PT-2026-34342 · Linux · Linux Kernel

Published 2026-04-22 · Updated 2026-04-23 · CVE-2026-31437

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A NULL pointer dereference occurs in the netfs unbuffered write() function during a retry operation. When a write subrequest is marked NETFS SREQ NEED RETRY, the system calls stream->prepare write() without verifying if the pointer is NULL. In filesystems like 9P, where the prepare write operation is not set, this leads to a crash if get user pages() fails with an -EFAULT error.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

CVE-2026-31437

Affected Products

Linux Kernel

References · 12

• https://security-tracker.debian.org/tracker/CVE-2026-31437 · Vendor Advisory
• https://git.kernel.org/stable/c/e9075e420a1eb3b52c60f3b95893a55e77419ce8 · Patch
• https://git.kernel.org/stable/c/a4d1b4ba9754bac3efebd06f583a44a7af52c0ab · Patch
• https://git.kernel.org/stable/c/7a5482f5ce891decbf36f2e6fab1e9fc4a76a684 · Patch
• https://cve.org/CVERecord?id=CVE-2026-31437 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-31437 · Security Note
• https://ubuntu.com/security/CVE-2026-31437 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-31437 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-31437 · Vendor Advisory
• https://twitter.com/infoflowcloud/status/2046982134133313948 · Twitter Post
• https://git.kernel.org/linus/e9075e420a1eb3b52c60f3b95893a55e77419ce8 · Note
• https://twitter.com/CVEnew/status/2046980057101398284 · Twitter Post