CVE-2026-53530 ratex-parser panics on `\verb` with a multibyte delimiter (UTF-8 byte-boundary slice)
An attacker can crash the application by providing a specific multibyte UTF-8 delimiter in a LaTeX verb command, causing a panic that aborts the process.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53530?
CVE-2026-53530 is a high-severity denial of service vulnerability in erweixin RaTeX, published on 21 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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(&str)` 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.
Which versions are affected by CVE-2026-53530?
2 open source packages ship an affected version, including ratex-parser.
| Package | Affected | Fixed in |
|---|---|---|
ratex-parser crates.io | All versions | 0.1.11 |
ratex-parser crates.io | All versions | 0.1.11 |
How do I fix CVE-2026-53530?
Upgrade ratex-parser to 0.1.11 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-53530 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-53530 exists.
Sources
Also known as GHSA-4hgp-59h5-gvrj.