TI-2026-41439 Aliases CVE-2026-57589 GHSA-w3gf-4959-2377

Use after free in OpenBSD

LOW 35CWE-416Published 2026-06-25 · Updated 2026-06-26

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-416 and the CVSS impact.

Summary

sys/kern/sysv_sem.c in OpenBSD through 7.9 has a use-after-free allowing local privilege escalation to root. This is a context switch use-after-free after tsleep in sys_semget().

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00169 6th 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
OpenBSD	OpenBSD	up to 7.9	—	No fix listed	CNA

OpenBSD VendorOpenBSD Affected up to 7.9 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:o:openbsd:openbsd::::::::	up to 7.9	Vulnerable	OpenBSD

cpe:2.3:o:openbsd:openbsd:*:*:*:*:*:*:*:* Versions up to 7.9 Vulnerable ·OpenBSD

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2026-57589
2026-10-03 Alias added: GHSA-w3gf-4959-2377

References

Patch 1

https://github.com/openbsd/src/commit/1957873d2063db11dab780eca75b5e629d1e838d

Advisory 1

https://openai.com/index/patch-the-planet/

TI-2002-00376 Integer overflow in xdr_array function in RPC servers for operating systems that use… CVSS 3.1CRITICAL 9.8
TI-2003-00437 Off-by-one error in the fb_realpath() function, as derived from the realpath function in… CVSS 3.1CRITICAL 9.8
TI-2007-05153 Stack-based buffer overflow in the cons_options function in options.c in dhcpd in OpenBSD… CVSS 2.0HIGH 7.2
TI-2001-00539 Buffer overflow in BSD-based telnetd telnet daemon on various operating systems allows… CVSS 2.0HIGH 10.0
TI-2026-40218 sppp_pap_input in sys/net/if_spppsubr.c in OpenBSD before 076e2b1 allows authentication… CVSS 3.1HIGH 8.3
TI-2004-00444 Heap-based buffer overflow in proxy_util.c for mod_proxy in Apache 1.3.25 to 1.3.31… CVSS 2.0HIGH 10.0

See all 200 →

Sources

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