CVE-2026-102633 libexpat 2.7.2 through 2.8.5 Integer Overflow in expat_realloc
Attackers can cause memory corruption or denial of service via malicious XML due to an integer overflow in libexpat's reallocation logic on 32-bit systems.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-102633?
CVE-2026-102633 is a high-severity vulnerability in libexpat, published on 29 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-190
Which versions are affected by CVE-2026-102633?
How do I fix CVE-2026-102633?
Upgrade to a fixed version.
Is CVE-2026-102633 being exploited?
There is no known exploitation of CVE-2026-102633 in the wild and no public exploit code.
Sources
Also known as ALPINE-CVE-2026-102633, AZL-105048, BELL-CVE-2026-102633, CLSA-2026-1791196479, CLSA-2026-1791791753, DEBIAN-CVE-2026-102633 and 3 more.