[ CVE-2026-118370 · Published 28 Oct 2026 ]
Vulnerability in libexpat
CVSS 8.2
EPSS <1%1 agency advisoryFix available
[ Description ]Official 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.
[ Fixes ]Fixes and patches
- Patch on github.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD
- Patch on github.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD
- Patch on github.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD
- Patch on vulncheck.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD
[ Advisories ]Government CERT advisories
-
BSI CERT-BundWID-SEC-2026-4214
expat: Multiple vulnerabilities allow denial of service Translated from German
[ References ]References
- github.com/libexpat/libexpatProduct
- github.com/libexpat/libexpat/blob/a76b1174c1ea52abb639a4c69d52b630a8a106a2/expat/lib/xm…Product
- github.com/libexpat/libexpat/commit/1bac53c4fc460a03cd9860f39501c7979f6750aePatch
- github.com/libexpat/libexpat/commit/621cb2c78b253ee023a86bc91d6ddb048481c04cPatch
- github.com/libexpat/libexpat/pull/1450Patch
- www.vulncheck.com/advisories/libexpat-through-2.9.0-integer-overflow-in-storeatts-via-a…PatchThird Party Advisory