Linux Kernel up to 6.19-rc4 free_choose_arg_map null pointer dereference

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.5$0-$5k0.00

Summaryinfo

A vulnerability marked as critical has been reported in Linux Kernel up to 6.19-rc4. Affected is the function free_choose_arg_map. The manipulation leads to null pointer dereference. This vulnerability is referenced as CVE-2026-22991. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.19-rc4. This issue affects the function free_choose_arg_map. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. The summary by CVE is:

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.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2026-22991 since 01/13/2026. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 296392 (Linux Distros Unpatched Vulnerability : CVE-2026-22991), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.248, 5.15.198, 6.1.161, 6.6.121, 6.12.66, 6.18.6 or 6.19-rc5 eliminates this vulnerability. Applying the patch 9b3730dabcf3764bfe3ff07caf55e641a0b45234/851241d3f78a5505224dc21c03d8692f530256b4/ec1850f663da64842614c86b20fe734be070c2ba/8081faaf089db5280c3be820948469f7c58ef8dd/c4c2152a858c0ce4d2bff6ca8c1d5b0ef9f2cbdf/f21c3fdb96833aac2f533506899fe38c19cf49d5/e3fe30e57649c551757a02e1cad073c47e1e075e is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (296392) and CERT Bund (WID-SEC-2026-0215). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • IBM QRadar SIEM
  • SUSE openSUSE
  • RESF Rocky Linux
  • NetApp ActiveIQ Unified Manager
  • Open Source Linux Kernel

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 296392
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-22991

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.248/5.15.198/6.1.161/6.6.121/6.12.66/6.18.6/6.19-rc5
Patch: 9b3730dabcf3764bfe3ff07caf55e641a0b45234/851241d3f78a5505224dc21c03d8692f530256b4/ec1850f663da64842614c86b20fe734be070c2ba/8081faaf089db5280c3be820948469f7c58ef8dd/c4c2152a858c0ce4d2bff6ca8c1d5b0ef9f2cbdf/f21c3fdb96833aac2f533506899fe38c19cf49d5/e3fe30e57649c551757a02e1cad073c47e1e075e

Timelineinfo

01/13/2026 CVE reserved
01/23/2026 +10 days Advisory disclosed
01/23/2026 +0 days VulDB entry created
05/18/2026 +115 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-22991 (🔒)
GCVE (CVE): GCVE-0-2026-22991
GCVE (VulDB): GCVE-100-342605
CERT Bund: WID-SEC-2026-0215 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 01/23/2026 17:34
Updated: 05/18/2026 03:45
Changes: 01/23/2026 17:34 (58), 01/25/2026 12:46 (2), 02/26/2026 20:20 (10), 03/27/2026 17:08 (7), 05/18/2026 03:45 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Want to know what is going to be exploited?

We predict KEV entries!