Vulnerability Report

CVE-2025-71263

Title: Buffer Overflow in UNIX v4 su command

Memory Corruption

Proof Of Concept

No public PoC currently indexed for CVE-2025-71263.

CWE Category CWE-120

Published Date Mar 13, 2026

Modified Date Jun 11, 2026

Exploit Status Not Found

Score 7.4 CVSS v3.1

Exploit Probability (EPSS)

0.18%

Vulnerability Summary

CVE-2025-71263: 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.

Impacted Vendors

sco 1

opengroup 1

Reference Links

https://discuss.systems/@ricci/115747843169814700 https://sigma-star.at/blog/2025/12/unix-v4-buffer-overflow/ https://www.spinellis.gr/blog/20251223/ https://www.tuhs.org/pipermail/tuhs/2026-January/032991.html

CVSS v3.1

Source Entity [email protected]

Severity HIGH

7.8

Attack Vector

LOCAL

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

UNCHANGED

RAW VECTOR CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H