CVE-2026-88839 Busybox: busybox: passwd/group parser writes heap pointers out of bounds due to stale tokenize() endpoint
An out-of-bounds write in BusyBox's passwd/group parser allows attackers to corrupt memory, potentially leading to code execution or privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-88839?
CVE-2026-88839 is a medium-severity memory corruption vulnerability in Red Hat Hardened Images, published on 23 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
BusyBox passwd/group tokenize() references a stale endpoint pointer after trimming, causing an out-of-bounds write of heap pointers.
Weakness: CWE-787
Which versions are affected by CVE-2026-88839?
How do I fix CVE-2026-88839?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-88839 being exploited?
There is no known exploitation of CVE-2026-88839 in the wild and no public exploit code.
Sources
Also known as AZL-105125, DEBIAN-CVE-2026-88839, ECHO-2dbb-f14e-a8c4, GHSA-fr4j-cp66-9wc4, UBUNTU-CVE-2026-88839.