CVE-2026-31579

Medium

In the Linux kernel, the following vulnerability has been resolved: wireguard: device: use exit_rtnl callback instead of manual rtnl_lock in pre_exit wg_netns_pre_exit() manually acquires rtnl_lock() inside the pernet .pre_exit callback. This causes a hung task when another thread holds rtnl_mutex - the cleanup_net workqueue (or the setup_net failure rollback path) blocks indefinitely in wg_netns_pre_exit() waiting to acquire the lock. Convert to .exit_rtnl, introduced in commit 7a60d91c690b ("net: Add ->exit_rtnl() hook to struct pernet_operations."), where the framework already holds RTNL and batches all callbacks under a single rtnl_lock()/rtnl_unlock() pair, eliminating the contention window. The rcu_assign_pointer(wg->creating_net, NULL) is safe to move from .pre_exit to .exit_rtnl (which runs after synchronize_rcu()) because all RCU readers of creating_net either use maybe_get_net() - which returns NULL for a dying namespace with zero refcount - or access net->user_ns which remains valid throughout the entire ops_undo_list sequence. [ Jason: added __net_exit and __read_mostly annotations that were missing. ]

Package Linux Kernel
Published 2026-04-24
Last modified 2026-04-27
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

Weakness type

CWE-476

CVE-2026-31579 is a NULL Pointer Dereference vulnerability

What is NULL Pointer Dereference?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.7.7, 5.8 and later are affected. Fixed in 6.18.24, 6.19.14, 7.0.1, 7.1-rc1 and their respective stable series.

Affected from
≥ 5.7.7 ≥ 5.8
Fixed in
✓ 6.18.24 6.18.x ✓ 6.19.14 6.19.x ✓ 7.0.1 7.0.x ✓ 7.1-rc1

References

The following references provide additional information about CVE-2026-31579 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

4 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2026-31579?

    CVE-2026-31579 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 5.7.7 onward and has been patched in 6.18.24, 6.19.14, 7.0.1 and others. CVE-2026-31579 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-31579?

    CVE-2026-31579 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-2026-31579?

    Yes — CVE-2026-31579 has been patched. Fixed versions include 6.18.24, 6.19.14, 7.0.1 and others. If you are running Linux kernel 5.7.7 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-31579 actively exploited?

    No — CVE-2026-31579 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is NULL Pointer Dereference (CWE-476)?

    The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. View CWE-476 on MITRE CWE →

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