PT-2026-34890 · Linux · Linux Kernel

CVE-2026-31538 · Published 2026-04-24 · Updated 2026-05-03

Positive Technologies (AI Summary)

CVSS v4.0

8.2

High

Base vector

AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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.

Exploit

Fix

Related Identifiers

CVE-2026-31538

Affected Products

Linux Kernel

References · 17

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31538.json · Exploit
• https://git.kernel.org/stable/c/66c082e3d4651e8629a393a9e182b01eb50fb0a3 · Patch
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-31538 · Vendor Advisory
• https://git.kernel.org/stable/c/26ad87a2cfb8c1384620d1693a166ed87303046e · Patch
• https://cve.org/CVERecord?id=CVE-2026-31538 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-31538 · Vendor Advisory
• https://git.kernel.org/stable/c/809cbd31aa4f87a1b889532244c9cf30eb022385 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-31538 · Security Note
• https://security-tracker.debian.org/tracker/CVE-2026-31538 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-31538 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2026-31538 · Vendor Advisory
• https://osv.dev/vulnerability/BELL-CVE-2026-31538 · Vendor Advisory
• https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git · Note
• https://twitter.com/infoflowcloud/status/2047799439276798038 · Twitter Post
• https://docs.bell-sw.com/security/cves/CVE-2026-31538 · Note