CVE-2026-22991

Medium

In the Linux kernel, the following vulnerability has been resolved: libceph: make free_choose_arg_map() resilient to partial allocation free_choose_arg_map() may dereference a NULL pointer if its caller fails after a partial allocation. For example, in decode_choose_args(), if allocation of arg_map->args fails, execution jumps to the fail label and free_choose_arg_map() is called. Since arg_map->size is updated to a non-zero value before memory allocation, free_choose_arg_map() will iterate over arg_map->args and dereference a NULL pointer. To prevent this potential NULL pointer dereference and make free_choose_arg_map() more resilient, add checks for pointers before iterating.

Package Linux Kernel
Published 2026-01-23
Last modified 2026-04-27
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-476

CVE-2026-22991 is a NULL Pointer Dereference vulnerability

What is NULL Pointer Dereference?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE

Affected versions

Linux kernel versions 4.13 and later are affected. Fixed in 5.10.248, 5.15.198, 6.1.161, 6.6.121, 6.12.66, 6.18.6, 6.19 and their respective stable series.

Affected from
≥ 4.13
Fixed in
✓ 5.10.248 5.10.x ✓ 5.15.198 5.15.x ✓ 6.1.161 6.1.x ✓ 6.6.121 6.6.x ✓ 6.12.66 6.12.x ✓ 6.18.6 6.18.x ✓ 6.19

References

The following references provide additional information about CVE-2026-22991 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

7 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2026-22991?

    CVE-2026-22991 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 4.13 onward and has been patched in 5.10.248, 5.15.198, 6.1.161 and others. CVE-2026-22991 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-22991?

    CVE-2026-22991 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2026-22991?

    Yes — CVE-2026-22991 has been patched. Fixed versions include 5.10.248, 5.15.198, 6.1.161 and others. If you are running Linux kernel 4.13 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-22991 actively exploited?

    No — CVE-2026-22991 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is NULL Pointer Dereference (CWE-476)?

    The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. View CWE-476 on MITRE CWE →

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