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ReviewHigh

CVE-2026-80521

Linux

In the Linux kernel, the following vulnerability has been resolved: af_unix: Unlink scc_entry in unix_del_edge(). Kyle Zeng reported that GC could free a dead SCC partially. The scenario is as follows: 1) Create two SCCs: X -. A <-> B ^--' 2) Run the following concurrently: 2-1) send() sk-B to sk-B from sk-X 2-2) close() both A and B At 2-1), there is a small window where unix_add_edges() publishes a new edge (B <-> B) to GC but its skb is not queued by skb_queue_tail(). If 2-2) completes before skb_queue_tail() and GC is triggered, it judges A <-> B as dead, but B is not freed because GC c...

CVSS
7.8
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.08.27
PRIORITY ASSESSMENT

Review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: af_unix: Unlink scc_entry in unix_del_edge(). Kyle Zeng reported that GC could free a dead SCC partially. The scenario is as follows: 1) Create two SCCs: X -. A <-> B ^--' 2) Run the following concurrently: 2-1) send() sk-B to sk-B from sk-X 2-2) close() both A and B At 2-1), there is a small window where unix_add_edges() publishes a new edge (B <-> B) to GC but its skb is not queued by skb_queue_tail(). If 2-2) completes before skb_queue_tail() and GC is triggered, it judges A <-> B as dead, but B is not freed because GC c...

Affected product and versions

Product
Linux
Affected versions
>= 4090fa373f0e763c43610853d2774b5979915959 < e3702470ced94fad74d71e2232f022d2eb752a6d, >= 4090fa373f0e763c43610853d2774b5979915959 < 594d905195024b228c962627ae5ae7c17bd582a4, >= 5dfd283f4651d04dbb70ceb9ae5c4a30eda3c52a, >= de7921631ff323369aa63a4324695ab54ea4047e, >= 6.1.141 < 6.2, >= 6.6.93 < 6.7, >= 6.10
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
Not available