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TI-2026-55534 Aliases CVE-2026-80521GHSA-g8mr-r59r-2xmq

af_unix: Unlink scc_entry in unix_del_edge().

Priority LOW 33Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

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 cannot collect the not-yet-queued skb holding the B <-> B edge. X -. A <-> B -. This edge is visible ^--' ^..' but skb is not This itself is not a problem since the next GC run will judge B as dead as well and free it finally. X -. A <.> B -. ^--' ^--' However, X's SCC forces the next GC to call unix_walk_scc_fast(), and it iterates over A through B's scc_entry. Let's unlink scc_entry before freeing the vertex in unix_del_edge().

Why it matters now

EPSS 0.00178 7th percentileScored 2026-11-07
Fix Fixed Linux (Linux): 6.1.189, 6.6.158, 6.12.111 +3Red Hat: 2 advisories

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux6.1.141 to before 6.1.189; 6.6.93 to before 6.6.1586.1.189, 6.6.158Patch availableCNA
LinuxLinux6.10 and later6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.1.10, 7.2Patch availableCNA
  • Linux VendorLinux Affected 6.1.141 to before 6.1.189; 6.6.93 to before 6.6.158 Fixed in 6.1.189, 6.6.158 Patch available CNA
  • Linux VendorLinux Affected 6.10 and later Fixed in 6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.1.10, 7.2 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*——Linux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions — — ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 6.1.189, 6.6.158
  • Fix · CNA Linux (Linux) Fixed in 6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.1.10, 7.2

Red Hat 2 advisories

  • RHSA-2026:81406 Released 2026-10-12 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • 10Base-SMTV kernel-modules-internal-6.12.0-211.65.1.el10_2
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.65.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.65.1.el10_2, kernel-64k-devel-6.12.0-211.65.1.el10_2 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.65.1.el10_2, kernel-64k-6.12.0-211.65.1.el10_2, kernel-64k-core-6.12.0-211.65.1.el10_2 +29
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.65.1.el10_2, libperf-6.12.0-211.65.1.el10_2
    • Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal-6.12.0-211.65.1.el10_2
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.65.1.el10_2, kernel-rt-64k-6.12.0-211.65.1.el10_2, kernel-rt-64k-core-6.12.0-211.65.1.el10_2 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.65.1.el10_2, kernel-rt-core-6.12.0-211.65.1.el10_2, kernel-rt-debug-6.12.0-211.65.1.el10_2 +9
  • RHSA-2026:77634 Released 2026-10-08 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) kernel-64k-debug-devel-6.12.0-55.109.1.el10_0, kernel-64k-debug-devel-matched-6.12.0-55.109.1.el10_0, kernel-64k-devel-6.12.0-55.109.1.el10_0 +12
    • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) kernel-6.12.0-55.109.1.el10_0, kernel-64k-6.12.0-55.109.1.el10_0, kernel-64k-core-6.12.0-55.109.1.el10_0 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) kernel-tools-libs-devel-6.12.0-55.109.1.el10_0, libperf-6.12.0-55.109.1.el10_0
    • Red Hat Enterprise Linux Real Time EUS (v. 10.0) kernel-rt-6.12.0-55.109.1.el10_0, kernel-rt-64k-6.12.0-55.109.1.el10_0, kernel-rt-64k-core-6.12.0-55.109.1.el10_0 +21
    • Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) kernel-rt-6.12.0-55.109.1.el10_0, kernel-rt-core-6.12.0-55.109.1.el10_0, kernel-rt-debug-6.12.0-55.109.1.el10_0 +11

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
10Base-SMTVFixed RHSA-2026:81406
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:81406
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:77634
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:81406
Red Hat Enterprise Linux BaseOS EUS (v. 10.0)Fixed RHSA-2026:77634
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:81406
Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)Fixed RHSA-2026:77634
Red Hat Enterprise Linux Hidden (v. 10)Fixed RHSA-2026:81406
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2026:81406
Red Hat Enterprise Linux Real Time EUS (v. 10.0)Fixed RHSA-2026:77634
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2026:81406
Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0)Fixed RHSA-2026:77634
Not affected: 4 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-80521
  2. 2026-10-03 Alias added: GHSA-g8mr-r59r-2xmq
  3. 2026-10-03 Fix available: Linux/Linux@2b6c2842692d08e7acaf32d1eb47f95def35f3fe, Linux/[email protected], Linux/[email protected] +1 · CNA
  4. 2026-10-03 2 new references · CNA
  5. 2026-10-08 Fix available: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux BaseOS EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) +2 · Red Hat
  6. 2026-10-09 Fix available: RHSA-2026:77634 · Red Hat
  7. 2026-10-13 Fix available: RHSA-2026:81406 · Red Hat
  8. 2026-10-13 Fix available: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10) +4 · Red Hat

References

Other 6

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
See all 21741 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences