OSV-2026-565 Heap-buffer-overflow in xmlFAParsePosCharGroup

Not scored Published

A heap buffer overflow in the XML parsing library allows attackers to cause denial of service or potentially execute code via crafted input.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
None listed

What is OSV-2026-565?

OSV-2026-565 is a memory corruption vulnerability in libxml2, published on 12 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=501547873

Crash type: Heap-buffer-overflow READ 1
Crash state:
xmlFAParsePosCharGroup
xmlFAParseCharGroup
xmlFAParseCharGroup

Which versions are affected by OSV-2026-565?

1 open source package ship an affected version, including libxml2.

PackageAffectedFixed in
libxml2 OSS-FuzzAll versionsNone

How do I fix OSV-2026-565?

No fix has been published for OSV-2026-565 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is OSV-2026-565 being exploited?

There is no known exploitation of OSV-2026-565 in the wild and no public exploit code.

Sources

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