{"id":"CVE-2026-53530","aliases":["EUVD-2026-64179","GHSA-4hgp-59h5-gvrj"],"status":"published","title":"ratex-parser panics on `\\verb` with a multibyte delimiter (UTF-8 byte-boundary slice)","description":"RaTeX is a KaTeX-compatible math rendering engine written in Rust. Prior to version 0.1.11, the public parser entrypoint `ratex_parser::parse(\u0026str)` panics on the 9-byte input `\\verbéxé` (i.e. `\\verb` followed by the non-ASCII delimiter `é`). When handling a `\\verb` command, the parser slices the verbatim argument with byte indices (`arg[1..arg.len() - 1]`); if the delimiter character is multibyte UTF-8, index `1` lands inside that character and Rust panics with *“byte index 1 is not a char boundary”*. Because RaTeX’s release profile sets `panic = \"abort\"` (`Cargo.toml:48`), the panic aborts the entire process — not just the current request/thread — making this a hard denial of service for any service that renders untrusted LaTeX. Version 0.1.11 fixes the issue.","severity":{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00428,"percentile":0.37305,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-1285","CWE-248","CWE-400"],"published":"2026-07-07T23:39:12Z","modified":"2026-10-28T02:30:57Z","fixes":[{"ecosystem":"crates.io","package":"ratex-parser","fixed_in":["0.1.11"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"crates.io","package":"ratex-parser","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.1.11"}]}]},{"source":"osv","ecosystem":"crates.io","package":"ratex-parser","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.1.11"}]}]}],"products":[{"vendor":"erweixin","product":"ratex"}],"references":[{"url":"https://github.com/erweixin/RaTeX/security/advisories/GHSA-4hgp-59h5-gvrj","tags":["x_refsource_CONFIRM","exploit","advisory","web"]},{"url":"https://github.com/advisories/GHSA-4hgp-59h5-gvrj"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53530.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53530","tags":["advisory"]},{"url":"https://github.com/erweixin/RaTeX","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-53530","title":"ratex-parser panics on `\\verb` with a multibyte delimiter (UTF-8 byte-boundary slice)","description":"RaTeX is a KaTeX-compatible math rendering engine written in Rust. Prior to version 0.1.11, the public parser entrypoint `ratex_parser::parse(\u0026str)` panics on the 9-byte input `\\verbéxé` (i.e. `\\verb` followed by the non-ASCII delimiter `é`). When handling a `\\verb` command, the parser slices the verbatim argument with byte indices (`arg[1..arg.len() - 1]`); if the delimiter character is multibyte UTF-8, index `1` lands inside that character and Rust panics with *“byte index 1 is not a char boundary”*. Because RaTeX’s release profile sets `panic = \"abort\"` (`Cargo.toml:48`), the panic aborts the entire process — not just the current request/thread — making this a hard denial of service for any service that renders untrusted LaTeX. Version 0.1.11 fixes the issue.","status":"published","published":"2026-08-21T21:31:12.665Z","modified":"2026-08-24T20:05:00.628Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna"}],"cwes":["CWE-248","CWE-400","CWE-1285"],"updated_at":"2026-11-02T14:19:59.761005Z"}],"euvd":[{"id":"EUVD-2026-64179","description":"RaTeX is a KaTeX-compatible math rendering engine written in Rust. Prior to version 0.1.11, the public parser entrypoint `ratex_parser::parse(\u0026str)` panics on the 9-byte input `\\verbéxé` (i.e. `\\verb` followed by the non-ASCII delimiter `é`). When handling a `\\verb` command, the parser slices the verbatim argument with byte indices (`arg[1..arg.len() - 1]`); if the delimiter character is multibyte UTF-8, index `1` lands inside that character and Rust panics with *“byte index 1 is not a char boundary”*. Because RaTeX’s release profile sets `panic = \"abort\"` (`Cargo.toml:48`), the panic aborts the entire process — not just the current request/thread — making this a hard denial of service for any service that renders untrusted LaTeX. Version 0.1.11 fixes the issue.","status":"published","published":"2026-08-21T21:31:12Z","modified":"2026-08-24T20:05:00Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T18:01:34.230875Z"}],"ghsa":[{"id":"GHSA-4hgp-59h5-gvrj","title":"ratex-parser panics on `\\verb` with a multibyte delimiter (UTF-8 byte-boundary slice)","description":"### Summary\n\nThe public parser entrypoint `ratex_parser::parse(\u0026str)` panics on the **9-byte** input `\\verbéxé` (i.e. `\\verb` followed by the non-ASCII delimiter `é`). When handling a `\\verb` command, the parser slices the verbatim argument with **byte** indices (`arg[1..arg.len() - 1]`); if the delimiter character is multibyte UTF-8, index `1` lands inside that character and Rust panics with *“byte index 1 is not a char boundary”*. Because RaTeX’s release profile sets `panic = \"abort\"` (`Cargo.toml:48`), the panic aborts the **entire process** — not just the current request/thread — making this a hard denial of service for any service that renders untrusted LaTeX.\n\n\n\n### Details\n\n\n## Affected code\n\n`crates/ratex-parser/src/parser.rs`, `parse_symbol_inner`:\n\n```rust\nif let Some(stripped) = text.strip_prefix(\"\\\\verb\") {       // parser.rs:901\n    self.consume();\n    let arg = stripped.to_string();                         // e.g. \"éxé\"\n    let star = arg.starts_with('*');\n    let arg = if star { \u0026arg[1..] } else { \u0026arg };          // parser.rs:905  (also byte-sliced)\n    if arg.len() \u003c 2 {                                      // byte length\n        return Err(ParseError::new(\"\\\\verb assertion failed\", Some(\u0026nucleus)));\n    }\n    let body = arg[1..arg.len() - 1].to_string();           // parser.rs:910  \u003c-- PANIC on multibyte delimiter\n    ...\n}\n```\n\nFor input `\\verbéxé`: `arg = \"éxé\"`, where `é` = `U+00E9` (bytes `C3 A9`). `arg.len()` is the **byte** length (5), the `\u003c 2` guard passes, and `arg[1..4]` starts at byte index 1 — inside the first `é` (bytes 0..2) — so the slice panics. The lexer groups `\\verb\u003cdelim\u003e…\u003cdelim\u003e` correctly with char semantics (`lexer.rs` `lex_verb`); only the parser mishandles it.\n\n### PoC\n\n\u003cimg width=\"1109\" height=\"205\" alt=\"image\" src=\"https://github.com/user-attachments/assets/cd4bc6ae-23dd-458f-826c-6ce4e85c7005\" /\u003e\n\n\n```\n$ printf '\\\\verb\\xc3\\xa9x\\xc3\\xa9\\n' | ./target/release/parse\nthread 'main' panicked at crates/ratex-parser/src/parser.rs:910:27:\nstart byte index 1 is not a char boundary; it is inside 'é' (bytes 0..2 of string)\nAborted (core dumped)            # exit 134 — panic=abort kills the whole process\n```\n\n### Impact\n\nAny application that renders untrusted LaTeX through RaTeX (web “render this math” endpoint, WASM in-browser use, the FFI embedded in another app) can be crashed by a tiny string. With `panic = \"abort\"` in release builds, the crash takes down the whole process / server, so a single malicious formula causes a full-service DoS (and, in batch pipelines, drops all queued work).\n\n## Remediation\n\nSlice by character boundaries instead of byte indices, mirroring the UTF-8-correct logic the lexer already uses. For example:\n\n```rust\nlet chars: Vec\u003cchar\u003e = arg.chars().collect();\nif chars.len() \u003c 2 { return Err(ParseError::new(\"\\\\verb assertion failed\", Some(\u0026nucleus))); }\nlet body: String = chars[1..chars.len() - 1].iter().collect();\n```\n\n(Apply the same char-aware handling to the `*` strip at `parser.rs:905`.) More broadly, consider not using `panic = \"abort\"` for builds embedded in long-running services, and/or wrapping parsing in `catch_unwind` at the FFI/WASM boundary — but the byte-slice fix is the direct correction.","status":"published","published":"2026-07-07T23:39:12Z","modified":"2026-07-07T23:39:13Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-248","CWE-400","CWE-1285"],"updated_at":"2026-11-02T14:40:40.389795Z"}],"nvd":[{"id":"CVE-2026-53530","description":"RaTeX is a KaTeX-compatible math rendering engine written in Rust. Prior to version 0.1.11, the public parser entrypoint `ratex_parser::parse(\u0026str)` panics on the 9-byte input `\\verbéxé` (i.e. `\\verb` followed by the non-ASCII delimiter `é`). When handling a `\\verb` command, the parser slices the verbatim argument with byte indices (`arg[1..arg.len() - 1]`); if the delimiter character is multibyte UTF-8, index `1` lands inside that character and Rust panics with *“byte index 1 is not a char boundary”*. Because RaTeX’s release profile sets `panic = \"abort\"` (`Cargo.toml:48`), the panic aborts the entire process — not just the current request/thread — making this a hard denial of service for any service that renders untrusted LaTeX. Version 0.1.11 fixes the issue.","status":"published","published":"2026-08-21T22:16:39.59Z","modified":"2026-10-12T16:10:00.22Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"}],"cwes":["CWE-248","CWE-400","CWE-1285"],"updated_at":"2026-11-02T14:12:40.665005Z"}],"osv":[{"id":"CVE-2026-53530","title":"ratex-parser panics on `\\verb` with a multibyte delimiter (UTF-8 byte-boundary slice)","description":"RaTeX is a KaTeX-compatible math rendering engine written in Rust. Prior to version 0.1.11, the public parser entrypoint `ratex_parser::parse(\u0026str)` panics on the 9-byte input `\\verbéxé` (i.e. `\\verb` followed by the non-ASCII delimiter `é`). When handling a `\\verb` command, the parser slices the verbatim argument with byte indices (`arg[1..arg.len() - 1]`); if the delimiter character is multibyte UTF-8, index `1` lands inside that character and Rust panics with *“byte index 1 is not a char boundary”*. Because RaTeX’s release profile sets `panic = \"abort\"` (`Cargo.toml:48`), the panic aborts the entire process — not just the current request/thread — making this a hard denial of service for any service that renders untrusted LaTeX. Version 0.1.11 fixes the issue.","status":"published","published":"2026-08-21T21:31:12.665Z","modified":"2026-10-28T02:30:57.559480153Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-1285","CWE-248","CWE-400"],"updated_at":"2026-11-02T15:45:08.132336Z"},{"id":"GHSA-4hgp-59h5-gvrj","title":"ratex-parser panics on `\\verb` with a multibyte delimiter (UTF-8 byte-boundary slice)","description":"### Summary\n\nThe public parser entrypoint `ratex_parser::parse(\u0026str)` panics on the **9-byte** input `\\verbéxé` (i.e. `\\verb` followed by the non-ASCII delimiter `é`). When handling a `\\verb` command, the parser slices the verbatim argument with **byte** indices (`arg[1..arg.len() - 1]`); if the delimiter character is multibyte UTF-8, index `1` lands inside that character and Rust panics with *“byte index 1 is not a char boundary”*. Because RaTeX’s release profile sets `panic = \"abort\"` (`Cargo.toml:48`), the panic aborts the **entire process** — not just the current request/thread — making this a hard denial of service for any service that renders untrusted LaTeX.\n\n\n\n### Details\n\n\n## Affected code\n\n`crates/ratex-parser/src/parser.rs`, `parse_symbol_inner`:\n\n```rust\nif let Some(stripped) = text.strip_prefix(\"\\\\verb\") {       // parser.rs:901\n    self.consume();\n    let arg = stripped.to_string();                         // e.g. \"éxé\"\n    let star = arg.starts_with('*');\n    let arg = if star { \u0026arg[1..] } else { \u0026arg };          // parser.rs:905  (also byte-sliced)\n    if arg.len() \u003c 2 {                                      // byte length\n        return Err(ParseError::new(\"\\\\verb assertion failed\", Some(\u0026nucleus)));\n    }\n    let body = arg[1..arg.len() - 1].to_string();           // parser.rs:910  \u003c-- PANIC on multibyte delimiter\n    ...\n}\n```\n\nFor input `\\verbéxé`: `arg = \"éxé\"`, where `é` = `U+00E9` (bytes `C3 A9`). `arg.len()` is the **byte** length (5), the `\u003c 2` guard passes, and `arg[1..4]` starts at byte index 1 — inside the first `é` (bytes 0..2) — so the slice panics. The lexer groups `\\verb\u003cdelim\u003e…\u003cdelim\u003e` correctly with char semantics (`lexer.rs` `lex_verb`); only the parser mishandles it.\n\n### PoC\n\n\u003cimg width=\"1109\" height=\"205\" alt=\"image\" src=\"https://github.com/user-attachments/assets/cd4bc6ae-23dd-458f-826c-6ce4e85c7005\" /\u003e\n\n\n```\n$ printf '\\\\verb\\xc3\\xa9x\\xc3\\xa9\\n' | ./target/release/parse\nthread 'main' panicked at crates/ratex-parser/src/parser.rs:910:27:\nstart byte index 1 is not a char boundary; it is inside 'é' (bytes 0..2 of string)\nAborted (core dumped)            # exit 134 — panic=abort kills the whole process\n```\n\n### Impact\n\nAny application that renders untrusted LaTeX through RaTeX (web “render this math” endpoint, WASM in-browser use, the FFI embedded in another app) can be crashed by a tiny string. With `panic = \"abort\"` in release builds, the crash takes down the whole process / server, so a single malicious formula causes a full-service DoS (and, in batch pipelines, drops all queued work).\n\n## Remediation\n\nSlice by character boundaries instead of byte indices, mirroring the UTF-8-correct logic the lexer already uses. For example:\n\n```rust\nlet chars: Vec\u003cchar\u003e = arg.chars().collect();\nif chars.len() \u003c 2 { return Err(ParseError::new(\"\\\\verb assertion failed\", Some(\u0026nucleus))); }\nlet body: String = chars[1..chars.len() - 1].iter().collect();\n```\n\n(Apply the same char-aware handling to the `*` strip at `parser.rs:905`.) More broadly, consider not using `panic = \"abort\"` for builds embedded in long-running services, and/or wrapping parsing in `catch_unwind` at the FFI/WASM boundary — but the byte-slice fix is the direct correction.","status":"published","published":"2026-07-07T23:39:12Z","modified":"2026-07-07T23:56:32.324787Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-1285","CWE-248","CWE-400"],"updated_at":"2026-11-02T15:46:37.148947Z"}]}}