Vulnerability in libexpat

[ Description ]Official description

libexpat versions 2.7.2 through 2.8.5 contain an integer overflow vulnerability in expat_realloc() function on 32-bit platforms when computing allocation sizes. Attackers supplying malicious XML to applications parsing with vulnerable libexpat can cause heap buffer overflow, memory corruption, or denial of service.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund29 Sep 2026WID-SEC-2026-3637

  expat: Vulnerability allows denial of service Translated from German

  Risk mediumCVE-2026-102633

[ References ]References

• github.com/libexpat/libexpat
• github.com/libexpat/libexpat/blob/R_2_8_5/expat/lib/xmlparse.c
• github.com/libexpat/libexpat/commit/209801d7fbaf07ab74bae8cb32dd2ab9e5846118
• github.com/libexpat/libexpat/pull/1392
• www.vulncheck.com/advisories/libexpat-2.7.2-through-2.8.5-integer-overflow-in-expat-rea…