OpenBSD 7.9 sysv_sem.c Use-After-Free CAUSE Priv Esc
CVE-2026-57589 Published on June 25, 2026

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().

NVD

Vulnerability Analysis

CVE-2026-57589 can be exploited with local system access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.

Attack Vector:
LOCAL
Attack Complexity:
HIGH
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

What is a Dangling pointer Vulnerability?

Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.

CVE-2026-57589 has been classified to as a Dangling pointer vulnerability or weakness.


Products Associated with CVE-2026-57589

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OpenBSD
 

Affected Versions

OpenBSD: