CVE-2026-118370EUVD-2026-111546GHSA-C6PW-VJR4-WWWR
libexpat through 2.9.0 Integer Overflow in storeAtts via attIndex and nPrefixes
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fix or patch referenced
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
libexpat, a widely used XML parsing library, is affected, and an attacker who supplies a very large XML document with an extremely high number of attributes in a single tag can cause an integer overflow. This can crash applications that use the library or corrupt heap memory.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original description
libexpat through 2.9.0 contains a signed integer overflow vulnerability in storeAtts() in lib/xmlparse.c that allows attackers to trigger out-of-bounds writes via oversized attribute counts. Attackers can supply a multi-gigabyte document with a start tag carrying over 2^30 attributes to overflow attIndex and nPrefixes, crashing applications or corrupting heap memory.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- libexpat libexpat
through 2.9.0