CVE-2026-80521

See a problem?
Please try reporting it to the source first.
Source
https://cve.org/CVERecord?id=CVE-2026-80521
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80521.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-80521
Downstream
Related
Published
2026-08-26T14:37:02Z
Modified
2026-10-13T20:42:02Z
Severity
  • 7.8 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
af_unix: Unlink scc_entry in unix_del_edge().
Details

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().

Database specific 
{
    "cna_assigner":  "Linux",
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80521.json"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
5dfd283f4651d04dbb70ceb9ae5c4a30eda3c52a
Fixed
2b6c2842692d08e7acaf32d1eb47f95def35f3fe
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
de7921631ff323369aa63a4324695ab54ea4047e
Fixed
6fda5c51b8e43a8440f76e65c89d9f95ddb2ef33
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
4090fa373f0e763c43610853d2774b5979915959
Fixed
1293fd69a50d188a5788b08ba3741a3e86be1608
Fixed
fe198b077864feafd4aa4b33b1a5ce26f50195a2
Fixed
e3702470ced94fad74d71e2232f022d2eb752a6d
Fixed
594d905195024b228c962627ae5ae7c17bd582a4
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
6.1.141
Fixed
6.1.189
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
6.6.93
Fixed
6.6.158

Affected versions

v6.*
v6.1.141
v6.1.142
v6.1.143
v6.1.144
v6.1.145
v6.1.146
v6.1.147
v6.1.148
v6.1.149
v6.1.150
v6.1.151
v6.1.152
v6.1.153
v6.1.154
v6.1.155
v6.1.156
v6.1.157
v6.1.158
v6.1.159
v6.1.160
v6.1.161
v6.1.162
v6.1.163
v6.1.164
v6.1.165
v6.1.166
v6.1.167
v6.1.168
v6.1.169
v6.1.170
v6.1.171
v6.1.172
v6.1.173
v6.1.174
v6.1.175
v6.1.176
v6.1.177
v6.1.178
v6.1.179
v6.1.180
v6.1.181
v6.1.182
v6.1.183
v6.1.184
v6.1.185
v6.1.186
v6.1.187
v6.1.188
v6.6.100
v6.6.101
v6.6.102
v6.6.103
v6.6.104
v6.6.105
v6.6.106
v6.6.107
v6.6.108
v6.6.109
v6.6.110
v6.6.111
v6.6.112
v6.6.113
v6.6.114
v6.6.115
v6.6.116
v6.6.117
v6.6.118
v6.6.119
v6.6.120
v6.6.121
v6.6.122
v6.6.123
v6.6.124
v6.6.125
v6.6.126
v6.6.127
v6.6.128
v6.6.129
v6.6.130
v6.6.131
v6.6.132
v6.6.133
v6.6.134
v6.6.135
v6.6.136
v6.6.137
v6.6.138
v6.6.139
v6.6.140
v6.6.141
v6.6.142
v6.6.143
v6.6.144
v6.6.145
v6.6.146
v6.6.147
v6.6.148
v6.6.149
v6.6.150
v6.6.151
v6.6.152
v6.6.153
v6.6.154
v6.6.155
v6.6.156
v6.6.157
v6.6.93
v6.6.94
v6.6.95
v6.6.96
v6.6.97
v6.6.98
v6.6.99

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80521.json"

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
6.1.189
Type
ECOSYSTEM
Events
Introduced
6.2.0
Fixed
6.6.158
Type
ECOSYSTEM
Events
Introduced
6.7.0
Fixed
6.12.111
Type
ECOSYSTEM
Events
Introduced
6.10.0
Fixed
6.18.53
Type
ECOSYSTEM
Events
Introduced
6.13.0
Fixed
7.1.10

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80521.json"