TI-2025-43387 Aliases CVE-2025-71263 GHSA-86j5-wh4f-79gm

Buffer overflow in AT&T Bell Labs UNIX

LOW 35CWE-120Published 2026-03-13 · Updated 2026-03-21

Key facts

Attack vector: Local
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Code execution
Confidentiality · integrity · availability: High · High · High
Fix status: No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-120 and the CVSS impact.

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.0019 8th percentileScored 2026-11-07

Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
AT&T Bell Labs	UNIX	4	—	No fix listed	CNA

UNIX VendorAT&T Bell Labs Affected 4 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:o:opengroup:unix:4:::::::*	4	Vulnerable	Opengroup

cpe:2.3:o:opengroup:unix:4:*:*:*:*:*:*:* Versions 4 Vulnerable ·Opengroup

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2025-71263
2026-10-03 Alias added: GHSA-86j5-wh4f-79gm

References

Other 4

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences