CVE-2025-71263
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine without logging in. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 7.4 HIGH (CVSS).
- Fix: none linked yet, which raises it.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-120 · Classic buffer overflow
- Record status
- Analyzed
Affected
- Opengroup Unix 4
Attack profile CVSS 3.1 · 7.4
- Attack vector
- Local
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2025-71263.md and follow it. Check whether this project is affected by CVE-2025-71263. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
References
- 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
- http://www.openwall.com/lists/oss-security/2026/03/20/6
- http://www.openwall.com/lists/oss-security/2026/03/21/4