OSV-2026-505 UNKNOWN READ in unsigned int Assimp::StreamReader<true, true>::Get<unsigned int>

Not scored Published

A memory corruption vulnerability in the Assimp library allows attackers to cause a denial of service via crafted Blender files.

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

What is OSV-2026-505?

OSV-2026-505 is a memory corruption vulnerability in assimp, published on 2 Apr 2026.

Official description

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=498284131

Crash type: UNKNOWN READ
Crash state:
unsigned int Assimp::StreamReader&lt;true, true&gt;::Get&lt;unsigned int&gt;
void Assimp::Blender::ConvertDispatcher&lt;int&gt;
void Assimp::Blender::Structure::ReadField&lt;2, int&gt;

Which versions are affected by OSV-2026-505?

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

PackageAffectedFixed in
assimp OSS-FuzzAll versionsNone

How do I fix OSV-2026-505?

No fix has been published for OSV-2026-505 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-2026-505 being exploited?

There is no known exploitation of OSV-2026-505 in the wild and no public exploit code.

Sources

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