CVE intelligence

CVE-2026-22991

Vulnerability intelligence

Published Jan 23, 2026Sources checked Oct 28, 2026

5.5MEDIUMCVSS out of 10

What this means

Review the available evidence

CVE-2026-22991 and is rated Medium severity with a CVSS score of 5.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Ubuntu Security Notices guidance

Vendor revision: Aug 21, 2026

Vendor remediation details

This update corrects flaws in the following subsystems: - Foo-over-UDP (FOU); - ARM64 architecture; - x86 architecture; - Block layer subsystem; - Drivers core; - Null block device driver; - Bluetooth drivers; - Counter interface drivers; - DMA engine subsystem; - DPLL subsystem; - GPIO subsystem; - GPU drivers; - I2C subsystem; - IIO ADC drivers; - IIO subsystem; - InfiniBand drivers; - On-Chip Interconnect management framework; - IOMMU subsystem; - IRQ chip drivers; - Modular ISDN driver; - LED subsystem; - Multiple devices driver; - Media drivers; - UACCE accelerator framework; - MMC subsystem; - Ethernet bonding driver; - Network drivers; - Mellanox network drivers; - Texas Instruments network drivers; - NVME drivers; - Device tree and open firmware driver; - PHY drivers; - x86 platfor

CISA KEVNot listedBased on the latest collected catalog

EPSS0.5%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-22991?

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.

Source: NVD