OpenBSD has a use-after-free allowing local privilege escalation to root

**CVE-2026-57589 Detail

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This CVE record has been marked for NVD enrichment efforts.

Description

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().

Metrics

• NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed. *

CVSS 4.0 Severity and Vector Strings:

NIST: NVD

** ** N/A

NVD assessment not yet provided.

CVSS 3.x Severity and Vector Strings:

NIST: NVD

Base Score: N/A

NVD assessment not yet provided.

CNA: MITRE

Base Score: 7.4 HIGH

Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS 2.0 Severity and Vector Strings:

NIST: NVD

Base Score: N/A

NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL	Source(s)	Tag(s)
https://github.com/openbsd/src/commit/1957873d2063db11dab780eca75b5e629d1e838d	MITRE
https://openai.com/index/patch-the-planet/	MITRE

Weakness Enumeration

CWE-ID	CWE Name	Source
CWE-416	Use After Free	MITRE

Change History

3 change records found show changes

CVE Modified by CISA-ADP 6/26/2026 1:16:31 AM

{"timestamp":"2026-06-25T12:34:51.474289Z","id":"CVE-2026-57589","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}

{"timestamp":"2026-06-25T00:00:00+00:00","id":"CVE-2026-57589","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}

Action	Type	Old Value	New Value
Changed	SSVC

CVE Modified by CISA-ADP 6/25/2026 9:16:49 AM

{"timestamp":"2026-06-25T12:34:51.474289Z","id":"CVE-2026-57589","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}

Action	Type	Old Value	New Value
Added	SSVC

New CVE Received from MITRE 6/24/2026 9:16:26 PM

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().

AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE-416

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

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

[{"vendor":"OpenBSD","product":"OpenBSD","defaultStatus":"unaffected","versions":[{"version":"0","lessThanOrEqual":"7.9","versionType":"custom","status":"affected"}]}]

Action	Type	Old Value	New Value
Added	Description
Added	CVSS V3.1
Added	CWE
Added	Reference
Added	Reference
Added	Affected

Quick Info

CVE Dictionary Entry: CVE-2026-57589 NVD Published Date: 06/24/2026 NVD Last Modified: 06/26/2026 ** Source:** MITRE