PT-2026-34890 · Linux · Linux Kernel

Published 2026-04-24 · Updated 2026-04-29 · CVE-2026-31538

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 6.18

Description A race condition exists in the SMB server logic used for managing receive credits. The process of counting posted recv io and granted credits is racy because a peer may consume a credit before the completion is processed in the recv done() function. This creates a window where credits are granted that do not actually exist.

Recommendations Update to version 6.18 or later.

Fix

Related Identifiers

CVE-2026-31538

Affected Products

Linux Kernel

References · 12

• https://ubuntu.com/security/CVE-2026-31538 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-31538 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-31538 · Vendor Advisory
• https://git.kernel.org/stable/c/809cbd31aa4f87a1b889532244c9cf30eb022385 · Patch
• https://cve.org/CVERecord?id=CVE-2026-31538 · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-31538 · Vendor Advisory
• https://git.kernel.org/stable/c/26ad87a2cfb8c1384620d1693a166ed87303046e · Patch
• https://git.kernel.org/stable/c/66c082e3d4651e8629a393a9e182b01eb50fb0a3 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-31538 · Security Note
• https://git.kernel.org/linus/26ad87a2cfb8c1384620d1693a166ed87303046e · Note
• https://twitter.com/CVEnew/status/2047798646851432726 · Twitter Post
• https://twitter.com/infoflowcloud/status/2047799439276798038 · Twitter Post