CVE-2025-71263 json
In UNIX Fourth Research Edition (v4), the su command is vulnerable to a buffer overflow due to the 'password' variable having a fixed size…
published 2026-03-13 7 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-208655
- cvss
- 7.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 10%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 7 mo ago
Exploit prediction
0.20% chance of exploitation in the next 30 days, higher than 10% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.4 | CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 3.1 | 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected products
- AT&T Bell Labs UNIX
Classification
- Weakness
-
- CWE-120 Buffer Copy without Checking Size of Input
References
-
sigma-star.at
/blog/2025/12/unix-v4-buffer-overflow/
press/media-coverage
-
tuhs.org
/pipermail/tuhs/2026-January/032991.html
issue-tracking, mailing-list
-
discuss.systems
/@ricci/115747843169814700
issue-tracking
-
spinellis.gr
/blog/20251223/
technical-description
-
openwall.com
/lists/oss-security/2026/03/20/6
issue-tracking, mailing-list
-
openwall.com
/lists/oss-security/2026/03/21/4
issue-tracking, mailing-list
Sources
- CVE List CVE-2025-71263
- NVD CVE-2025-71263
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.