CVE-2026-40943

CVE-2026-40943 is a high-severity vulnerability with a CVSS 4.0 base score of 8.7. 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-362.

Key facts

Description

Oxia is a metadata store and coordination system. Prior to 0.16.2, a race condition between session heartbeat processing and session closure can cause the server to panic with send on closed channel. The heartbeat() method uses a blocking channel send while holding a mutex, and under specific timing with concurrent close() calls, this can lead to either a deadlock (channel buffer full) or a panic (send on closed channel after TOCTOU gap in KeepAlive). This vulnerability is fixed in 0.16.2.

Frequently asked questions

What is CVE-2026-40943?
Oxia is a metadata store and coordination system. Prior to 0.16.2, a race condition between session heartbeat processing and session closure can cause the server to panic with send on closed channel. The heartbeat() method uses a blocking channel send while holding a mutex, and under specific timing with concurrent close() calls, this can lead to either a deadlock (channel buffer full) or a panic (send on closed channel after TOCTOU gap in KeepAlive). This vulnerability is fixed in 0.16.2.
How severe is CVE-2026-40943?
CVE-2026-40943 has a CVSS 4.0 base score of 8.7, rated high severity.
Is CVE-2026-40943 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-40943?
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-2026-40943 have an EU (EUVD) identifier?
Yes. CVE-2026-40943 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-24498.
When was CVE-2026-40943 published?
CVE-2026-40943 was published on 2026-04-21 and last updated on 2026-06-17.

References

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