PatchTheCVECVE-2026-43121: In the Linux kernel, the following vulnerability has been resolved: io_uring/zcrx: fix user_ref race between
CVE-2026-43121 is a medium-severity flaw (CVSS 4.7) affecting linux kernel. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
In the Linux kernel, the following vulnerability has been resolved: io_uring/zcrx: fix user_ref race between scrub and refill paths The io_zcrx_put_niov_uref() function uses a non-atomic check-then-decrement pattern (atomic_read followed by separate atomic_dec) to manipulate user_refs. This is serialized against other callers by rq_lock, but io_zcrx_scrub() modifies the same counter with atomic_xchg() WITHOUT holding rq_lock. On SMP systems, t
Why this priority
- On your watchlist
A fixed release or distro patch exists.
Risk facts
| CVSS score | 4.7 (Medium) |
| Attack vector | Local |
| Attack complexity | High |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 0.1% (top 99%) |
| CISA exploited list | No |
| Weakness | CWE-362 |
| Published | 2026-05-06 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-43121?
linux kernel: upgrade to 6.18.16, 6.19.6. Exact commands for each OS are on this page.
Is CVE-2026-43121 being exploited?
CVE-2026-43121 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-43121 affect?
CVE-2026-43121 affects linux kernel. Severity is medium (CVSS 4.7). In the Linux kernel, the following vulnerability has been resolved: io_uring/zcrx: fix user_ref race between scrub and refill paths The io_zcrx_put_niov_uref() function uses a non-atomic check-then-decrement pattern (atomic_read followed
How urgent is CVE-2026-43121?
Priority 22/100. On your watchlist
Software pages
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