CVE-2025-71263 Memory corruption in UNIX
A local buffer overflow in the su command allows attackers to gain root privileges on unsupported UNIX v4 systems.
- 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-2025-71263?
CVE-2025-71263 is a high-severity memory corruption vulnerability in AT&T Bell Labs UNIX, published on 13 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In UNIX Fourth Research Edition (v4), the su command is vulnerable to a buffer overflow due to the 'password' variable having a fixed size of 100 bytes. A local user can exploit this to gain root privileges. It is unlikely that UNIX v4 is running anywhere outside of a very small number of lab environments. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.
Weakness: CWE-120
Which versions are affected by CVE-2025-71263?
It affects 1 product.
Products include Opengroup Unix.
How do I fix CVE-2025-71263?
No fix has been published for CVE-2025-71263 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-2025-71263 being exploited?
There is no known exploitation of CVE-2025-71263 in the wild and no public exploit code.
Sources
Also known as GHSA-86j5-wh4f-79gm.