PT-2026-34343 · Linux · Linux Kernel

Published 2026-04-22 · Updated 2026-04-23 · CVE-2026-31438

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 kernel BUG occurs in the netfs limit iter() function when handling ITER KVEC iterators. This happens when a process crashes and the kernel attempts to write a core dump to a 9P filesystem, causing kernel write() to create an ITER KVEC iterator. Because netfs limit iter() only supports ITER FOLIOQ, ITER BVEC, and ITER XARRAY types, it triggers a BUG() for any other type, including ITER KVEC.

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-2026-31438

Affected Products

Linux Kernel

References · 15

• https://osv.dev/vulnerability/UBUNTU-CVE-2026-31438 · Vendor Advisory
• https://git.kernel.org/stable/c/67e467a11f62ff64ad219dc6aa5459e132c79d14 · Patch
• https://git.kernel.org/stable/c/4bc2d72c7695cedf6d4e1a558924903c2b28a78e · Patch
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-31438 · Vendor Advisory
• https://osv.dev/vulnerability/BELL-CVE-2026-31438 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-31438 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-31438 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-31438 · Security Note
• https://git.kernel.org/stable/c/18c2e20b42dd21db599e42d05ddaeeb647b2bb6d · Patch
• https://git.kernel.org/stable/c/00d6df7115f6972370974212de9088087820802e · Patch
• https://cve.org/CVERecord?id=CVE-2026-31438 · Security Note
• https://docs.bell-sw.com/security/cves/CVE-2026-31438 · Note
• https://twitter.com/CVEnew/status/2046980055893446873 · Twitter Post
• https://twitter.com/infoflowcloud/status/2046982065820704902 · Twitter Post
• https://git.kernel.org/linus/67e467a11f62ff64ad219dc6aa5459e132c79d14 · Note