CVE-2026-43491: In the Linux kernel, the following vulnerability has been resolved: net: qrtr: ns: Limit the maximum server registration per node Current code does ...

Description

In the Linux kernel, the following vulnerability has been resolved: net: qrtr: ns: Limit the maximum server registration per node Current code does no bound checking on the number of servers added per node. A malicious client can flood NEW_SERVER messages and exhaust memory. Fix this issue by limiting the maximum number of server registrations to 256 per node. If the NEW_SERVER message is received for an old port, then don't restrict it as it will get replaced. While at it, also rate limit the error messages in the failure path of qrtr_ns_worker(). Note that the limit of 256 is chosen based on the current platform requirements. If requirement changes in the future, this limit can be increased.

Metrics

CVSS 3.1

5.5/10

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

EPSS Probability

0.19%

8.4th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	>= 5.7, < 6.6.140
Linux	Linux Kernel	>= 6.7, < 6.12.86
Linux	Linux Kernel	>= 6.13, < 6.18.27
Linux	Linux Kernel	>= 6.19, < 7.0.4

References

Timeline

Published: May 19, 2026
Last Modified: Jun 26, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-43491?

In the Linux kernel, the following vulnerability has been resolved: net: qrtr: ns: Limit the maximum server registration per node Current code does no bound checking on the number of servers added per node. A malicious client can flood NEW_SERVER messages and exhaust memory. Fix this issue by limiting the maximum number of server registrations to 256 per node. If the NEW_SERVER message is received for an old port, then don't restrict it as it will get replaced. While at it, also rate limit the error messages in the failure path of qrtr_ns_worker(). Note that the limit of 256 is chosen based on the current platform requirements. If requirement changes in the future, this limit can be increased.

How severe is CVE-2026-43491?

CVE-2026-43491 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.19% probability of exploitation in the next 30 days.

How do I fix CVE-2026-43491?

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.