CVE-2026-74345
Linux kernel siw use-after-free via malformed MPA request
Is CVE-2026-74345 being exploited?
Not confirmed. CVE-2026-74345 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 0.44% probability of exploitation in the next 30 days.
How severe is CVE-2026-74345?
CVE-2026-74345 is rated Critical with a CVSS score of 9.8. 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-2026-74345?
Yes. A fix has been recorded for CVE-2026-74345. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-74345 affect?
CVE-2026-74345 affects Linux kernel (siw RDMA/iWARP driver), Hosts with RDMA/iWARP enabled, Data center/HPC servers using iWARP. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-74345?
Apply vendor/kernel siw patch or disable siw/iWARP until patched.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote attacker sending malformed MPA can trigger kernel use-after-free, leading to crash (DoS) or possible kernel-level privilege escalation/exec.
Immediate action required
- affected>= 6c52fdc244b5ccc468006fd65a504d4ee33743c7 and < b28d513393f81e2de00f82970487a9d001557e4e
- affected>= 6c52fdc244b5ccc468006fd65a504d4ee33743c7 and < f6183983ce1ff254d629a333739082b39d7c5eb6
- affected>= 6c52fdc244b5ccc468006fd65a504d4ee33743c7 and < b6cf763eee0a932792bef64ceaca568d324192fc
- affected>= 6c52fdc244b5ccc468006fd65a504d4ee33743c7 and < ea4f6f6c53577fb3f05dbd78b15e586772d49831
- affected5.3
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.