CVE-2026-57589
OpenBSD Use-After-Free Privilege Escalation
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().
INFO
Published Date :
June 25, 2026, 1:16 a.m.
Last Modified :
July 10, 2026, 4:39 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 8254265b-2729-46b6-b9e3-3dfca2d5bfca | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update OpenBSD to a version that includes the fix.
- Apply the security patch for sysv_sem.c.
- Review system configurations for potential weaknesses.
- Monitor for any related system instability.
Public PoC/Exploit Available at Github
CVE-2026-57589 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-57589.
| URL | Resource |
|---|---|
| https://github.com/openbsd/src/commit/1957873d2063db11dab780eca75b5e629d1e838d | Patch |
| https://openai.com/index/patch-the-planet/ | Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-57589 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-57589
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-57589 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-57589 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jul. 10, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Added CPE Configuration OR *cpe:2.3:o:openbsd:openbsd:*:*:*:*:*:*:*:* versions up to (including) 7.9 Added Reference Type MITRE: https://github.com/openbsd/src/commit/1957873d2063db11dab780eca75b5e629d1e838d Types: Patch Added Reference Type MITRE: https://openai.com/index/patch-the-planet/ Types: Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 26, 2026
Action Type Old Value New Value Changed SSVC {'id': 'CVE-2026-57589', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-25T12:34:51.474289Z'} {'id': 'CVE-2026-57589', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-25T00:00:00+00:00'} -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 25, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-57589', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-25T12:34:51.474289Z'} -
New CVE Received by [email protected]
Jun. 25, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'OpenBSD', 'product': 'OpenBSD', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'custom', 'lessThanOrEqual': '7.9'}], 'defaultStatus': 'unaffected'}] Added 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(). Added CVSS V3.1 AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-416 Added Reference https://github.com/openbsd/src/commit/1957873d2063db11dab780eca75b5e629d1e838d Added Reference https://openai.com/index/patch-the-planet/