CVE-2026-31535

MEDIUMCVSS 4.7/10EPSS 0.09%

Last modified

CVE-2026-31535 is a medium-severity vulnerability rated 4.7/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: smb: client: make use of smbdirect_socket.recv_io.credits.available The logic off managing recv credits by counting posted recv_io and granted credits is racy. That's because the peer might already consumed a credit, but between receiving the incoming recv at the hardware and processing the completion in the 'recv_done' functions we likely have a window where we grant credits, which don't really exist. So we better have a decicated counter for the available credits, which will be incremented when we posted new recv buffers and drained when we grant the credits to the peer.. EPSS estimates a 0.09% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: make use of smbdirect_socket.recv_io.credits.available The logic off managing recv credits by counting posted recv_io and granted credits is racy. That's because the peer might already consumed a credit, but between receiving the incoming recv at the hardware and processing the completion in the 'recv_done' functions we likely have a window where we grant credits, which don't really exist. So we better have a decicated counter for the available credits, which will be incremented when we posted new recv buffers and drained when we grant the credits to the peer.

Metrics

CVSS 3.1
4.7/10

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
0.09%

0.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
LinuxLinux Kernel>= 6.18, < 6.18.11
LinuxLinux Kernel>= 6.19, < 6.19.1

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-31535?
In the Linux kernel, the following vulnerability has been resolved: smb: client: make use of smbdirect_socket.recv_io.credits.available The logic off managing recv credits by counting posted recv_io and granted credits is racy. That's because the peer might already consumed a credit, but between receiving the incoming recv at the hardware and processing the completion in the 'recv_done' functions we likely have a window where we grant credits, which don't really exist. So we better have a decicated counter for the available credits, which will be incremented when we posted new recv buffers and drained when we grant the credits to the peer.
How severe is CVE-2026-31535?
CVE-2026-31535 has a CVSS score of 4.7/10 (MEDIUM severity). The EPSS model estimates a 0.09% probability of exploitation in the next 30 days.
How do I fix CVE-2026-31535?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-31535?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST