Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
AV AC PR UI S C I A CVSS EPSS %ile KEV L H L N U N N H 4.7 .0025 16.7 —
AFFECTED Product Versions Fixed Linux 21a091b970cdbcf3e8ff829234b51be6f9192766 – — Linux 6.1 – 6.1.125
TIMELINE Dec 29 Reserved by Linux Jan 20 Published (CNA: Linux) Jul 30 RESCORED — CVE-2025-21655 (Linux). CVSS 7.8 → 4.7 (NVD).
In the Linux kernel, the following vulnerability has been resolved: io_uring/eventfd: ensure io_eventfd_signal() defers another RCU period io_eventfd_do_signal() is invoked from an RCU callback, but when dropping the reference to the io_ev_fd, it calls io_eventfd_free() directly if the refcount drops to zero. This isn't correct, as any potential freeing of the io_ev_fd should be deferred another RCU grace period. Just call io_eventfd_put() rather than open-code the dec-and-test and free, which will correctly defer it another RCU grace period.
| Date | Event | Detail |
|---|---|---|
| December 29, 2024 | Reserved | Reserved by Linux |
| January 20, 2025 | Published | Published (CNA: Linux) |
| July 30, 2026 | RESCORED | RESCORED — CVE-2025-21655 (Linux). CVSS 7.8 → 4.7 (NVD). |
Authoritative record: CVE-2025-21655 at cve.org
Vendors: linux
Weaknesses: CWE-416
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2025-21655 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.