# CVE-2025-10990: Ruby REXML ReDoS in hex numeric character references

Source: https://junglewise.ai/threats/cve-2025-10990-ruby-rexml-redos-in-hex-numeric-character-references  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-02-27. Updated: 2026-06-26  
License: CC BY 4.0 with a link back

CVE-2025-10990 · Severity: high · CVSS 7.5 · Published 2026-02-27

REXML is a popular Ruby library used for parsing XML data. A flaw in how it handles specific character references allows a remote attacker to crash the application or cause it to become unresponsive by sending a specially crafted XML document. This results in a denial-of-service (DoS) condition, potentially disrupting business operations and service availability for applications relying on this library, including Red Hat Satellite.

Vendors: [Puppet](https://junglewise.ai/threats/vendors/puppet), [Ruby](https://junglewise.ai/threats/vendors/ruby).

## Quick answers

**Is CVE-2025-10990 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-10990 being exploited in the wild.

**How severe is CVE-2025-10990?** High severity, with a CVSS score of 7.5, published 27 February 2026.

**Which products and versions are affected?** Puppet-Agent 8.8.1-3.el8sat, 8.8.1-3.el9sat; Ruby REXML Before 3.3.9.

**Is there a fix for CVE-2025-10990?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2025-10990 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2025-10990?** Check whether you run Puppet-Agent or Ruby REXML at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A flaw was found in the REXML library's handling of hex numeric character references (&#x...;) within XML documents. The vulnerability is classified as a Regular Expression Denial of Service (ReDoS) caused by inefficient regular expression complexity (CWE-1333). A remote, unauthenticated attacker can exploit this by providing a crafted XML document that triggers catastrophic backtracking during regex parsing, leading to excessive CPU consumption and service unavailability. This issue represents an incomplete fix for a previous vulnerability (CVE-2024-49761). Patches have been released by the Ruby REXML maintainers and downstream vendors like Red Hat.

## Affected products

- Ruby REXML Before 3.3.9
- Red Hat Satellite 6.16, 6.17
- Puppet puppet-agent 8.8.1-3.el8sat, 8.8.1-3.el9sat

## Timeline

- 2024-10-28: other: Original vulnerability CVE-2024-49761 disclosed
- 2025-10-08: advisory: Red Hat published security advisory RHSA-2025:17606
- 2026-02-27: disclosed: NVD published CVE-2025-10990 record

## References

- [https://www.redhat.com/en/technologies/management/satellite](https://www.redhat.com/en/technologies/management/satellite)
- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)
- [https://access.redhat.com/errata/RHSA-2025:17606](https://access.redhat.com/errata/RHSA-2025:17606)
- [https://access.redhat.com/errata/RHSA-2025:17613](https://access.redhat.com/errata/RHSA-2025:17613)
- [https://access.redhat.com/errata/RHSA-2025:17693](https://access.redhat.com/errata/RHSA-2025:17693)
- [https://access.redhat.com/security/cve/CVE-2025-10990](https://access.redhat.com/security/cve/CVE-2025-10990)
- [https://bugzilla.redhat.com/show_bug.cgi?id=2398216](https://bugzilla.redhat.com/show_bug.cgi?id=2398216)