CVE-2026-23436

Medium

In the Linux kernel, the following vulnerability has been resolved: net: shaper: protect from late creation of hierarchy We look up a netdev during prep of Netlink ops (pre- callbacks) and take a ref to it. Then later in the body of the callback we take its lock or RCU which are the actual protections. The netdev may get unregistered in between the time we take the ref and the time we lock it. We may allocate the hierarchy after flush has already run, which would lead to a leak. Take the instance lock in pre- already, this saves us from the race and removes the need for dedicated lock/unlock callbacks completely. After all, if there's any chance of write happening concurrently with the flush - we're back to leaking the hierarchy. We may take the lock for devices which don't support shapers but we're only dealing with SET operations here, not taking the lock would be optimizing for an error case.

Package Linux Kernel
Published 2026-04-03
Last modified 2026-04-23
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected versions

Linux kernel versions 6.13 and later are affected. Fixed in 6.18.20, 6.19.10, 7.0 and their respective stable series.

Affected from
≥ 6.13
Fixed in
✓ 6.18.20 6.18.x ✓ 6.19.10 6.19.x ✓ 7.0

References

The following references provide additional information about CVE-2026-23436 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Frequently asked questions

  • What is CVE-2026-23436?

    CVE-2026-23436 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 6.13 onward and has been patched in 6.18.20, 6.19.10 and 7.0. CVE-2026-23436 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-23436?

    CVE-2026-23436 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2026-23436?

    Yes — CVE-2026-23436 has been patched. Fixed versions include 6.18.20, 6.19.10 and 7.0. If you are running Linux kernel 6.13 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-23436 actively exploited?

    No — CVE-2026-23436 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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