REXML has DoS condition when parsing malformed XML file
Date: 2025-09
Affected: rubygems/rexml
Attack vector: dos
Category: vulnerability-disclosure
Severity: Low
CVE: CVE-2025-58767
CWE: CWE-400
CWE-776

### Impact The REXML gems from 3.3.3 to 3.4.1 have a DoS vulnerability when parsing XML containing multiple XML declarations. If you need to parse untrusted XMLs, you may be impacted to these vulnerabilities. ### Patches REXML gems 3.4.2 or later include the patches to fix these vulnerabilities. ### Workarounds Don't parse untrusted XMLs. ### References * https://www.ruby-lang.org/en/news/2025/09/18/dos-rexml-cve-2025-58767/ : An announcement on www.ruby-lang.org


Mitigations:

Architectural layers (MAESTRO):