What is CVE-2026-45983?

CVE-2026-45983 is a unscored severity Linux kernel vulnerability, affecting Linux kernel versions from 2.6.30 onward and patched in 5.10.252, 5.15.202, 6.1.165 and others. CVE-2026-45983 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-45983?

CVE-2026-45983 has a CVSS score of pending NVD analysis out of 10, rated awaiting scoring severity.

Is there a patch available for CVE-2026-45983?

Yes, CVE-2026-45983 has been patched. Fixed versions include 5.10.252, 5.15.202, 6.1.165 and others. If you are running Linux kernel 2.6.30 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-45983 actively exploited?

CVE-2026-45983 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-45983

In the Linux kernel, the following vulnerability has been resolved: nfsd: never defer requests during idmap lookup During v4 request compound arg decoding, some ops (e.g. SETATTR) can trigger idmap lookup upcalls. When those upcall responses get delayed beyond the allowed time limit, cache_check() will mark the request for deferral and cause it to be dropped. This prevents nfs4svc_encode_compoundres from being executed, and thus the session slot flag NFSD4_SLOT_INUSE never gets cleared. Subsequent client requests will fail with NFSERR_JUKEBOX, given that the slot will be marked as in-use, making the SEQUENCE op fail. Fix this by making sure that the RQ_USEDEFERRAL flag is always clear during nfs4svc_decode_compoundargs(), since no v4 request should ever be deferred.

Package Linux Kernel

Published 2026-05-27

Last modified 2026-05-27

Patch available

Yes

Affected versions

Linux kernel versions 2.6.30 and later are affected. Fixed in 5.10.252, 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.14, 6.19.4, 7.0 and their respective stable series.

Affected from

≥ 2.6.30

Fixed in

✓ 5.10.252 5.10.x ✓ 5.15.202 5.15.x ✓ 6.1.165 6.1.x ✓ 6.6.128 6.6.x ✓ 6.12.75 6.12.x ✓ 6.18.14 6.18.x ✓ 6.19.4 6.19.x ✓ 7.0

References

The following references provide additional information about CVE-2026-45983 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/063a6f22478ef929625000a2caf54667725c1dfd
Patch
Kernel patch commit
https://git.kernel.org/stable/c/243f71ed873ff3feeb6f9b5cb145d63f7188b4c4
Patch
Kernel patch commit
https://git.kernel.org/stable/c/3a72c7dedc99b321e0f267e4e999e5baf07c4593
Patch

8 patch commits total View all on NVD

Frequently asked questions

What is CVE-2026-45983?

CVE-2026-45983 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 2.6.30 onward and has been patched in 5.10.252, 5.15.202, 6.1.165 and others. CVE-2026-45983 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
Is there a patch available for CVE-2026-45983?

Yes — CVE-2026-45983 has been patched. Fixed versions include 5.10.252, 5.15.202, 6.1.165 and others. If you are running Linux kernel 2.6.30 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-45983 actively exploited?

No — CVE-2026-45983 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.