CVE-2026-80521

Local privilege escalation via stale SCC entry

Published Aug 26, 2026 · Updated Aug 26, 2026

Use-after-free in Linux kernel AF_UNIX garbage collection allows local users to escalate privileges through concurrent socket operations. unix_add_edges() exposes a new edge before its socket buffer is queued, while concurrent close() and GC can free only part of an SCC and leave scc_entry linked for unix_walk_scc_fast() to dereference. An unprivileged local user can repeatedly race self-send and close operations; successful exploitation corrupts kernel memory, while failure can panic the host.

CVSS severity7.8
High
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux kernel AF_UNIX garbage collection allows local users to escalate privileges through concurrent socket operations. unix_add_edges() exposes a new edge before its socket buffer is queued, while concurrent close() and GC can free only part of an SCC and leave scc_entry linked for unix_walk_scc_fast() to dereference. An unprivileged local user can repeatedly race self-send and close operations; successful exploitation corrupts kernel memory, while failure can panic the host.

The record

CVE
CVE-2026-80521
Published
Aug 26, 2026
Updated
Aug 26, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-367, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4090fa373f0e763c43610853d2774b5979915959 <594d905195024b228c962627ae5ae7c17bd582a4
  2. Affected versionversion=4090fa373f0e763c43610853d2774b5979915959 <e3702470ced94fad74d71e2232f022d2eb752a6d
  3. Affected versionversion=5dfd283f4651d04dbb70ceb9ae5c4a30eda3c52a
  4. Affected versionversion=6.10
  5. Affected versionversion=6.1.141 <6.2
  6. Affected versionversion=6.6.93 <6.7
  7. Affected versionversion=de7921631ff323369aa63a4324695ab54ea4047e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4090fa373f0e763c43610853d2774b5979915959 <594d905195024b228c962627ae5ae7c17bd582a4; version=4090fa373f0e763c43610853d2774b5979915959 <e3702470ced94fad74d71e2232f022d2eb752a6d; version=5dfd283f4651d04dbb70ceb9ae5c4a30eda3c52a; version=6.10; version=6.1.141 <6.2; version=6.6.93 <6.7; version=de7921631ff323369aa63a4324695ab54ea4047e

Published CVSS scores

7.8Linux Kernel CVE TeamCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-367Time-of-check Time-of-use Race Condition
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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