CVE-2026-57589

CVE-2026-57589 is a high-severity vulnerability with a CVSS 3.x base score of 7.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-416.

Key facts

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().

Frequently asked questions

What is CVE-2026-57589?
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().
How severe is CVE-2026-57589?
CVE-2026-57589 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over local access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-57589 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-57589?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-57589 have an EU (EUVD) identifier?
Yes. CVE-2026-57589 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39156.
When was CVE-2026-57589 published?
CVE-2026-57589 was published on 2026-06-25 and last updated on 2026-06-26.

References

Other CWE-416 (Use After Free) vulnerabilities

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