CVE-2026-34961 barebox ext4 Extent Parsing Out-of-Bounds Read

Medium 6.9 Published 11 May 2026 Updated 18 Jul 2026

Attackers can trigger heap out-of-bounds reads in barebox via malicious ext4 images, potentially leaking memory or causing crashes during boot.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-34961?

CVE-2026-34961 is a medium-severity memory corruption vulnerability in barebox, published on 11 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

barebox prior to version 2026.04.0 contains out-of-bounds read vulnerabilities in ext4 extent parsing due to missing validation of the eh_entries field against buffer capacity in fs/ext4/ext4_common.c. Attackers can supply a malicious ext4 filesystem image via USB, SD card, or network boot to trigger heap out-of-bounds reads during boot-time filesystem parsing, potentially redirecting reads to arbitrary disk offsets.

Weakness: CWE-125

Which versions are affected by CVE-2026-34961?

It affects 1 product.

Products include Pengutronix Barebox.

How do I fix CVE-2026-34961?

No fix has been published for CVE-2026-34961 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 CVE-2026-34961 being exploited?

There is no known exploitation of CVE-2026-34961 in the wild and no public exploit code.

Sources

Also known as GHSA-vv9w-vff6-5rx9.