CVE-2026-63980

High

In the Linux kernel, the following vulnerability has been resolved: net/handshake: Use spin_lock_bh for hn_lock nvmet_tcp_state_change(), a socket callback that runs in BH context, can reach handshake_req_cancel() via nvmet_tcp_schedule_release_queue() and tls_handshake_cancel(). handshake_req_cancel() acquires hn->hn_lock with plain spin_lock(). If a process-context thread on the same CPU holds hn->hn_lock when a softirq invokes the cancel path, the lock attempt deadlocks. This is the only caller that invokes tls_handshake_cancel() from BH context; every other consumer calls it from process context. Deferring the cancel to process context in the NVMe target is not straightforward: nvmet_tcp_schedule_release_queue() must call tls_handshake_cancel() atomically with its state transition to DISCONNECTING. If the cancel were deferred, the handshake completion callback could fire in the window before the cancel runs, observe the unexpected state, and return without dropping its kref on the queue. Reworking that interlock is considerably more invasive than hardening the handshake lock. Convert all hn->hn_lock acquisitions from spin_lock/spin_unlock to spin_lock_bh/spin_unlock_bh so the lock is never taken with softirqs enabled.

Package Linux Kernel
Published 2026-07-19
Last modified 2026-07-30
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.5

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

Affected versions

Linux kernel versions 6.7 and later are affected. Fixed in 6.12.93, 6.18.35, 7.0.12, 7.1 and their respective stable series.

Affected from
≥ 6.7
Fixed in
✓ 6.12.93 6.12.x ✓ 6.18.35 6.18.x ✓ 7.0.12 7.0.x ✓ 7.1

References

4 total

Frequently asked questions

  • What is CVE-2026-63980?

    CVE-2026-63980 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10 . It affects Linux kernel versions from 6.7 onward and has been patched in 6.12.93, 6.18.35, 7.0.12 and others. CVE-2026-63980 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-63980?

    CVE-2026-63980 has a CVSS score of 7.5 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2026-63980?

    Yes. CVE-2026-63980 has been patched. Fixed versions include 6.12.93, 6.18.35, 7.0.12 and others. If you are running Linux kernel 6.7 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-63980 actively exploited?

    No. CVE-2026-63980 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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