diff --git a/Cargo.lock b/Cargo.lock
index 7cac8e8f3ad..a66cdfe34e1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -37,32 +37,31 @@ checksum = "4b46cbb362ab8752921c97e041f5e366ee6297bd428a31275b9fcf1e380f7299"
 
 [[package]]
 name = "anstyle"
-version = "1.0.13"
+version = "1.0.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5192cca8006f1fd4f7237516f40fa183bb07f8fbdfedaa0036de5ea9b0b45e78"
+checksum = "940b3a0ca603d1eade50a4846a2afffd5ef57a9feac2c0e2ec2e14f9ead76000"
 
 [[package]]
 name = "anyhow"
-version = "1.0.100"
+version = "1.0.102"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a23eb6b1614318a8071c9b2521f36b424b2c83db5eb3a0fead4a6c0809af6e61"
+checksum = "7f202df86484c868dbad7eaa557ef785d5c66295e41b460ef922eca0723b842c"
 
 [[package]]
 name = "argh"
-version = "0.1.13"
+version = "0.1.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "34ff18325c8a36b82f992e533ece1ec9f9a9db446bd1c14d4f936bac88fcd240"
+checksum = "211818e820cda9ca6f167a64a5c808837366a6dfd807157c64c1304c486cd033"
 dependencies = [
  "argh_derive",
  "argh_shared",
- "rust-fuzzy-search",
 ]
 
 [[package]]
 name = "argh_derive"
-version = "0.1.13"
+version = "0.1.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "adb7b2b83a50d329d5d8ccc620f5c7064028828538bdf5646acd60dc1f767803"
+checksum = "c442a9d18cef5dde467405d27d461d080d68972d6d0dfd0408265b6749ec427d"
 dependencies = [
  "argh_shared",
  "proc-macro2",
@@ -72,9 +71,9 @@ dependencies = [
 
 [[package]]
 name = "argh_shared"
-version = "0.1.13"
+version = "0.1.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a464143cc82dedcdc3928737445362466b7674b5db4e2eb8e869846d6d84f4f6"
+checksum = "e5ade012bac4db278517a0132c8c10c6427025868dca16c801087c28d5a411f1"
 dependencies = [
  "serde",
 ]
@@ -87,9 +86,9 @@ checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
 
 [[package]]
 name = "bumpalo"
-version = "3.19.1"
+version = "3.20.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5dd9dc738b7a8311c7ade152424974d8115f2cdad61e8dab8dac9f2362298510"
+checksum = "5d20789868f4b01b2f2caec9f5c4e0213b41e3e5702a50157d699ae31ced2fcb"
 
 [[package]]
 name = "cast"
@@ -99,9 +98,9 @@ checksum = "37b2a672a2cb129a2e41c10b1224bb368f9f37a2b16b612598138befd7b37eb5"
 
 [[package]]
 name = "cc"
-version = "1.2.54"
+version = "1.2.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6354c81bbfd62d9cfa9cb3c773c2b7b2a3a482d569de977fd0e961f6e7c00583"
+checksum = "e1e928d4b69e3077709075a938a05ffbedfa53a84c8f766efbf8220bb1ff60e1"
 dependencies = [
  "find-msvc-tools",
  "jobserver",
@@ -117,9 +116,9 @@ checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
 [[package]]
 name = "chrono"
-version = "0.4.43"
+version = "0.4.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fac4744fb15ae8337dc853fee7fb3f4e48c0fbaa23d0afe49c447b4fab126118"
+checksum = "c673075a2e0e5f4a1dde27ce9dee1ea4558c7ffe648f576438a20ca1d2acc4b0"
 dependencies = [
  "iana-time-zone",
  "js-sys",
@@ -157,18 +156,18 @@ dependencies = [
 
 [[package]]
 name = "clap"
-version = "4.5.55"
+version = "4.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3e34525d5bbbd55da2bb745d34b36121baac88d07619a9a09cfcf4a6c0832785"
+checksum = "b193af5b67834b676abd72466a96c1024e6a6ad978a1f484bd90b85c94041351"
 dependencies = [
  "clap_builder",
 ]
 
 [[package]]
 name = "clap_builder"
-version = "4.5.55"
+version = "4.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "59a20016a20a3da95bef50ec7238dbd09baeef4311dcdd38ec15aba69812fb61"
+checksum = "714a53001bf66416adb0e2ef5ac857140e7dc3a0c48fb28b2f10762fc4b5069f"
 dependencies = [
  "anstyle",
  "clap_lex",
@@ -176,9 +175,9 @@ dependencies = [
 
 [[package]]
 name = "clap_lex"
-version = "0.7.7"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c3e64b0cc0439b12df2fa678eae89a1c56a529fd067a9115f7827f1fffd22b32"
+checksum = "c8d4a3bb8b1e0c1050499d1815f5ab16d04f0959b233085fb31653fbfc9d98f9"
 
 [[package]]
 name = "core-foundation-sys"
@@ -188,9 +187,9 @@ checksum = "773648b94d0e5d620f64f280777445740e61fe701025087ec8b57f45c791888b"
 
 [[package]]
 name = "criterion"
-version = "0.8.1"
+version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4d883447757bb0ee46f233e9dc22eb84d93a9508c9b868687b274fc431d886bf"
+checksum = "950046b2aa2492f9a536f5f4f9a3de7b9e2476e575e05bd6c333371add4d98f3"
 dependencies = [
  "alloca",
  "anes",
@@ -213,9 +212,9 @@ dependencies = [
 
 [[package]]
 name = "criterion-plot"
-version = "0.8.1"
+version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ed943f81ea2faa8dcecbbfa50164acf95d555afec96a27871663b300e387b2e4"
+checksum = "d8d80a2f4f5b554395e47b5d8305bc3d27813bacb73493eb1001e8f76dae29ea"
 dependencies = [
  "cast",
  "itertools",
@@ -274,9 +273,9 @@ checksum = "48c757948c5ede0e46177b7add2e67155f70e33c07fea8284df6576da70b3719"
 
 [[package]]
 name = "find-msvc-tools"
-version = "0.1.8"
+version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8591b0bcc8a98a64310a2fae1bb3e9b8564dd10e381e6e28010fde8e8e8568db"
+checksum = "5baebc0774151f905a1a2cc41989300b1e6fbb29aff0ceffa1064fdd3088d582"
 
 [[package]]
 name = "getrandom"
@@ -345,9 +344,9 @@ dependencies = [
 
 [[package]]
 name = "itoa"
-version = "1.0.17"
+version = "1.0.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "92ecc6618181def0457392ccd0ee51198e065e016d1d527a7ac1b6dc7c1f09d2"
+checksum = "8f42a60cbdf9a97f5d2305f08a87dc4e09308d1276d28c869c684d7777685682"
 
 [[package]]
 name = "jobserver"
@@ -361,9 +360,9 @@ dependencies = [
 
 [[package]]
 name = "js-sys"
-version = "0.3.85"
+version = "0.3.91"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8c942ebf8e95485ca0d52d97da7c5a2c387d0e7f0ba4c35e93bfcaee045955b3"
+checksum = "b49715b7073f385ba4bc528e5747d02e66cb39c6146efb66b781f131f0fb399c"
 dependencies = [
  "once_cell",
  "wasm-bindgen",
@@ -371,9 +370,9 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.180"
+version = "0.2.183"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bcc35a38544a891a5f7c865aca548a982ccb3b8650a5b06d0fd33a10283c56fc"
+checksum = "b5b646652bf6661599e1da8901b3b9522896f01e736bad5f723fe7a3a27f899d"
 
 [[package]]
 name = "log"
@@ -400,9 +399,9 @@ dependencies = [
 
 [[package]]
 name = "memchr"
-version = "2.7.6"
+version = "2.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f52b00d39961fc5b2736ea853c9cc86238e165017a493d1d5c8eac6bdc4cc273"
+checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
 
 [[package]]
 name = "num-traits"
@@ -415,9 +414,9 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.21.3"
+version = "1.21.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"
+checksum = "9f7c3e4beb33f85d45ae3e3a1792185706c8e16d043238c593331cc7cd313b50"
 
 [[package]]
 name = "oorandom"
@@ -486,9 +485,9 @@ dependencies = [
 
 [[package]]
 name = "quote"
-version = "1.0.44"
+version = "1.0.45"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "21b2ebcf727b7760c461f091f9f0f539b77b8e87f2fd88131e7f1b433b3cece4"
+checksum = "41f2619966050689382d2b44f664f4bc593e129785a36d6ee376ddf37259b924"
 dependencies = [
  "proc-macro2",
 ]
@@ -521,9 +520,9 @@ dependencies = [
 
 [[package]]
 name = "regex"
-version = "1.12.2"
+version = "1.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "843bc0191f75f3e22651ae5f1e72939ab2f72a4bc30fa80a066bd66edefc24d4"
+checksum = "e10754a14b9137dd7b1e3e5b0493cc9171fdd105e0ab477f51b72e7f3ac0e276"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -533,9 +532,9 @@ dependencies = [
 
 [[package]]
 name = "regex-automata"
-version = "0.4.13"
+version = "0.4.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5276caf25ac86c8d810222b3dbb938e512c55c6831a10f3e6ed1c93b84041f1c"
+checksum = "6e1dd4122fc1595e8162618945476892eefca7b88c52820e74af6262213cae8f"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -544,9 +543,9 @@ dependencies = [
 
 [[package]]
 name = "regex-syntax"
-version = "0.8.8"
+version = "0.8.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a2d987857b319362043e95f5353c0535c1f58eec5336fdfcf626430af7def58"
+checksum = "dc897dd8d9e8bd1ed8cdad82b5966c3e0ecae09fb1907d58efaa013543185d0a"
 
 [[package]]
 name = "roxmltree"
@@ -557,12 +556,6 @@ dependencies = [
  "memchr",
 ]
 
-[[package]]
-name = "rust-fuzzy-search"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a157657054ffe556d8858504af8a672a054a6e0bd9e8ee531059100c0fa11bb2"
-
 [[package]]
 name = "rustversion"
 version = "1.0.22"
@@ -642,9 +635,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "2.0.114"
+version = "2.0.117"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d4d107df263a3013ef9b1879b0df87d706ff80f65a86ea879bd9c31f9b307c2a"
+checksum = "e665b8803e7b1d2a727f4023456bbbbe74da67099c585258af0ad9c5013b9b99"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -663,9 +656,9 @@ dependencies = [
 
 [[package]]
 name = "toml-span"
-version = "0.6.0"
+version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5c6532e5b62b652073bff0e2050ef57e4697a853be118d6c57c32b59fffdeaab"
+checksum = "f22ba417d437b5fa5dcba6c27dbd6c14f38845315b724d89fed73b7a426451b7"
 dependencies = [
  "smallvec",
 ]
@@ -684,9 +677,9 @@ dependencies = [
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.22"
+version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9312f7c4f6ff9069b165498234ce8be658059c6728633667c526e27dc2cf1df5"
+checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
 
 [[package]]
 name = "version_check"
@@ -715,9 +708,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.108"
+version = "0.2.114"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "64024a30ec1e37399cf85a7ffefebdb72205ca1c972291c51512360d90bd8566"
+checksum = "6532f9a5c1ece3798cb1c2cfdba640b9b3ba884f5db45973a6f442510a87d38e"
 dependencies = [
  "cfg-if",
  "once_cell",
@@ -728,9 +721,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.108"
+version = "0.2.114"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "008b239d9c740232e71bd39e8ef6429d27097518b6b30bdf9086833bd5b6d608"
+checksum = "18a2d50fcf105fb33bb15f00e7a77b772945a2ee45dcf454961fd843e74c18e6"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -738,9 +731,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.108"
+version = "0.2.114"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5256bae2d58f54820e6490f9839c49780dff84c65aeab9e772f15d5f0e913a55"
+checksum = "03ce4caeaac547cdf713d280eda22a730824dd11e6b8c3ca9e42247b25c631e3"
 dependencies = [
  "bumpalo",
  "proc-macro2",
@@ -751,18 +744,18 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.108"
+version = "0.2.114"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1f01b580c9ac74c8d8f0c0e4afb04eeef2acf145458e52c03845ee9cd23e3d12"
+checksum = "75a326b8c223ee17883a4251907455a2431acc2791c98c26279376490c378c16"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "web-sys"
-version = "0.3.85"
+version = "0.3.91"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "312e32e551d92129218ea9a2452120f4aabc03529ef03e4d0d82fb2780608598"
+checksum = "854ba17bb104abfb26ba36da9729addc7ce7f06f5c0f90f3c391f8461cca21f9"
 dependencies = [
  "js-sys",
  "wasm-bindgen",
@@ -869,9 +862,9 @@ dependencies = [
 
 [[package]]
 name = "winresource"
-version = "0.1.30"
+version = "0.1.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e287ced0f21cd11f4035fe946fd3af145f068d1acb708afd248100f89ec7432d"
+checksum = "0986a8b1d586b7d3e4fe3d9ea39fb451ae22869dcea4aa109d287a374d866087"
 dependencies = [
  "version_check",
 ]
@@ -884,18 +877,18 @@ checksum = "d7249219f66ced02969388cf2bb044a09756a083d0fab1e566056b04d9fbcaa5"
 
 [[package]]
 name = "zerocopy"
-version = "0.8.35"
+version = "0.8.47"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fdea86ddd5568519879b8187e1cf04e24fce28f7fe046ceecbce472ff19a2572"
+checksum = "efbb2a062be311f2ba113ce66f697a4dc589f85e78a4aea276200804cea0ed87"
 dependencies = [
  "zerocopy-derive",
 ]
 
 [[package]]
 name = "zerocopy-derive"
-version = "0.8.35"
+version = "0.8.47"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0c15e1b46eff7c6c91195752e0eeed8ef040e391cdece7c25376957d5f15df22"
+checksum = "0e8bc7269b54418e7aeeef514aa68f8690b8c0489a06b0136e5f57c4c5ccab89"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -904,9 +897,9 @@ dependencies = [
 
 [[package]]
 name = "zmij"
-version = "1.0.17"
+version = "1.0.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "02aae0f83f69aafc94776e879363e9771d7ecbffe2c7fbb6c14c5e00dfe88439"
+checksum = "b8848ee67ecc8aedbaf3e4122217aff892639231befc6a1b58d29fff4c2cabaa"
 
 [[package]]
 name = "zstd"
diff --git a/crates/edit/Cargo.toml b/crates/edit/Cargo.toml
index 3858b585cce..30818ec76ed 100644
--- a/crates/edit/Cargo.toml
+++ b/crates/edit/Cargo.toml
@@ -30,7 +30,7 @@ stdext.workspace = true
 lsh.workspace = true
 # The default toml crate bundles its dependencies with bad compile times. Thanks.
 # Thankfully toml-span exists. FWIW the alternative is yaml-rust (without the 2 suffix).
-toml-span = { version = "0.6", default-features = false }
+toml-span = { version = "0.7", default-features = false }
 
 [target.'cfg(windows)'.build-dependencies]
 winresource = { version = "0.1", default-features = false }
diff --git a/crates/lsh/src/runtime.rs b/crates/lsh/src/runtime.rs
index c3af7aac4a4..e9e767786a2 100644
--- a/crates/lsh/src/runtime.rs
+++ b/crates/lsh/src/runtime.rs
@@ -303,6 +303,7 @@ impl<'pa, 'ps, 'pc> Runtime<'pa, 'ps, 'pc> {
             let mut i = 0;
 
             while i < needle.len() {
+                debug_assert!(off + i < haystack.len());
                 let a = *a.add(i);
                 let b = *b.add(i);
                 i += 1;
@@ -323,11 +324,14 @@ impl<'pa, 'ps, 'pc> Runtime<'pa, 'ps, 'pc> {
                 return false;
             }
 
+            debug_assert!(off.checked_add(needle.len()).is_some_and(|end| end <= haystack.len()));
+
             let a = haystack.as_ptr().add(off);
             let b = needle.as_ptr();
             let mut i = 0;
 
             while i < needle.len() {
+                debug_assert!(off + i < haystack.len());
                 // str in PrefixInsensitive(str) is expected to be lowercase, printable ASCII.
                 let a = a.add(i).read().to_ascii_lowercase();
                 let b = b.add(i).read();
@@ -438,16 +442,19 @@ pub struct Registers {
 impl Registers {
     #[inline(always)]
     pub fn get(&self, reg: Register) -> u32 {
+        debug_assert!((reg as usize) < Register::COUNT);
         unsafe { self.as_ptr().add(reg as usize).read() }
     }
 
     #[inline(always)]
     pub fn set(&mut self, reg: Register, val: u32) {
+        debug_assert!((reg as usize) < Register::COUNT);
         unsafe { self.as_mut_ptr().add(reg as usize).write(val) }
     }
 
     #[inline(always)]
     fn save_registers(&self, vec: &mut Vec<u32>) {
+        const _: () = assert!(2 + 14 <= Register::COUNT);
         unsafe { vec.extend_from_slice(std::slice::from_raw_parts(self.as_ptr().add(2), 14)) };
     }
 
@@ -546,12 +553,14 @@ macro_rules! instruction_decode {
     }) => {{
         #[inline(always)]
         fn dec_reg_single(bytes: &[u8], off: usize) -> Register {
+            debug_assert!(off < bytes.len());
             let b = unsafe { *bytes.as_ptr().add(off) as usize };
             Register::from_usize(b & 0xf)
         }
 
         #[inline(always)]
         fn dec_reg_pair(bytes: &[u8], off: usize) -> (Register, Register) {
+            debug_assert!(off < bytes.len());
             let b = unsafe { *bytes.as_ptr().add(off) as usize };
             let dst = Register::from_usize(b & 0xf);
             let src = Register::from_usize(b >> 4);
@@ -560,6 +569,7 @@ macro_rules! instruction_decode {
 
         #[inline(always)]
         fn dec_u32(bytes: &[u8], off: usize) -> u32 {
+            debug_assert!(off + 4 <= bytes.len());
             unsafe { (bytes.as_ptr().add(off) as *const u32).read_unaligned() }
         }
 
diff --git a/fuzz/.gitignore b/fuzz/.gitignore
new file mode 100644
index 00000000000..e844c5b0c5d
--- /dev/null
+++ b/fuzz/.gitignore
@@ -0,0 +1,4 @@
+artifacts
+corpus
+coverage
+target
diff --git a/fuzz/Cargo.lock b/fuzz/Cargo.lock
new file mode 100644
index 00000000000..8948fcbbf8a
--- /dev/null
+++ b/fuzz/Cargo.lock
@@ -0,0 +1,178 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "arbitrary"
+version = "1.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3d036a3c4ab069c7b410a2ce876bd74808d2d0888a82667669f8e783a898bf1"
+
+[[package]]
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+checksum = "e1e928d4b69e3077709075a938a05ffbedfa53a84c8f766efbf8220bb1ff60e1"
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+ "find-msvc-tools",
+ "jobserver",
+ "libc",
+ "shlex",
+]
+
+[[package]]
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+
+[[package]]
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+version = "1.2.1"
+dependencies = [
+ "libc",
+ "lsh",
+ "stdext",
+ "toml-span",
+ "windows-sys",
+ "winresource",
+]
+
+[[package]]
+name = "edit-fuzz"
+version = "0.0.0"
+dependencies = [
+ "edit",
+ "libfuzzer-sys",
+ "stdext",
+]
+
+[[package]]
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+ "cfg-if",
+ "libc",
+ "r-efi",
+ "wasip2",
+]
+
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+ "getrandom",
+ "libc",
+]
+
+[[package]]
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+checksum = "b5b646652bf6661599e1da8901b3b9522896f01e736bad5f723fe7a3a27f899d"
+
+[[package]]
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+ "arbitrary",
+ "cc",
+]
+
+[[package]]
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+ "stdext",
+]
+
+[[package]]
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+
+[[package]]
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+ "libc",
+]
+
+[[package]]
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+ "smallvec",
+]
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+checksum = "9517f9239f02c069db75e65f174b3da828fe5f5b945c4dd26bd25d89c03ebcf5"
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+ "wit-bindgen",
+]
+
+[[package]]
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+ "windows-link",
+]
+
+[[package]]
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+dependencies = [
+ "version_check",
+]
+
+[[package]]
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diff --git a/fuzz/Cargo.toml b/fuzz/Cargo.toml
new file mode 100644
index 00000000000..74cbba4060a
--- /dev/null
+++ b/fuzz/Cargo.toml
@@ -0,0 +1,22 @@
+[package]
+name = "edit-fuzz"
+version = "0.0.0"
+publish = false
+edition = "2024"
+
+[package.metadata]
+cargo-fuzz = true
+
+[workspace]
+
+[dependencies]
+edit = { path = "../crates/edit" }
+stdext = { path = "../crates/stdext" }
+libfuzzer-sys = "0.4"
+
+[[bin]]
+name = "highlighter"
+path = "fuzz_targets/highlighter.rs"
+test = false
+doc = false
+bench = false
diff --git a/fuzz/fuzz_targets/highlighter.rs b/fuzz/fuzz_targets/highlighter.rs
new file mode 100644
index 00000000000..50b62679678
--- /dev/null
+++ b/fuzz/fuzz_targets/highlighter.rs
@@ -0,0 +1,23 @@
+#![no_main]
+
+use edit::lsh::{Highlighter, LANGUAGES};
+use libfuzzer_sys::fuzz_target;
+use stdext::arena::scratch_arena;
+
+fuzz_target!(|data: &[u8]| {
+    if data.is_empty() {
+        return;
+    }
+
+    for lang in LANGUAGES {
+        let mut highlighter = Highlighter::new(&data, lang);
+
+        loop {
+            let arena = scratch_arena(None);
+            let highlights = highlighter.parse_next_line(&arena);
+            if highlights.is_empty() {
+                break;
+            }
+        }
+    }
+});