CVE-2026-74631
Linux kernel SMC splice refcount bug causes use-after-free enabling kernel crash or escalation.
Is CVE-2026-74631 being exploited?
Not confirmed. CVE-2026-74631 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.14% probability of exploitation in the next 30 days.
How severe is CVE-2026-74631?
CVE-2026-74631 is rated High with a CVSS score of 8.4. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-74631?
Yes. A fix has been recorded for CVE-2026-74631. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-74631 affect?
CVE-2026-74631 affects Linux kernel (SMC subsystem), Linux servers with SMC/SMC-R or RDMA enabled. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-74631?
Apply kernel/vendor security updates and reboot affected hosts.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Local attacker can trigger a kernel use-after-free via SMC splice, causing denial-of-service or local privilege escalation to root.
Patch when possible
- affected>= 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f and < 7ddc7af2ae7fc5a0c0635b245c0824c8b76de5cb
- affected>= 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f and < 07ad246529d136d5ef441d5ab4c305d132ff3090
- affected>= 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f and < c841789e456ec6751342fa800639ce8e82ff0e6b
- affected>= 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f and < af02c67ce654356c58db20a0bb2db33ace3b07a8
- affected>= 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f and < ca8342b5fc24c249fdb998468f6a168b457c67e5
- affected>= 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f and < 0b7d54cedea5cb158e21925ae0c6c2f5c87ed2a0
- affected>= 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f and < 4515c78f4d9fd577270f012efeb062ea58b3682d
- affected>= 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f and < 5d9686af2976741bbd79b150d1c9e60b81e7f12e
- affected4.18
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.