CVE-2026-80668

Stale master access via expectation timer race

Published Aug 28, 2026 · Updated Aug 28, 2026

Use-after-free in Linux netfilter conntrack expectations allows attackers to access a freed master object during timer expiry. The expectation timer can race with removal, and a failed timer deletion leaves exp->master pointing to an already released conntrack object. The published record does not identify an attacker-controlled trigger or bound the consequence beyond stale-pointer access in the kernel packet path.

CVSS severityUnavailable
Unscored
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Use-after-free in Linux netfilter conntrack expectations allows attackers to access a freed master object during timer expiry. The expectation timer can race with removal, and a failed timer deletion leaves exp->master pointing to an already released conntrack object. The published record does not identify an attacker-controlled trigger or bound the consequence beyond stale-pointer access in the kernel packet path.

The record

CVE
CVE-2026-80668
Published
Aug 28, 2026
Updated
Aug 28, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Aug 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=497f99b26fffdc5635706d1b4811f1ed8ee21a5b
  2. Affected versionversion=5e1c1d22268ae710c238342c8030c21daf298168
  3. Affected versionversion=6.1.176 <6.2
  4. Affected versionversion=6.12.94 <6.13
  5. Affected versionversion=6.18.24 <6.19
  6. Affected versionversion=6.19.14 <6.20
  7. Affected versionversion=6.6.143 <6.7
  8. Affected versionversion=7.0
  9. Affected versionversion=9e1196d27ef496f404c76f7a9d03761142d991c4
  10. Affected versionversion=bffcaad9afdfe45d7fc777397d3b83c1e3ebffe5 <7ec786f4230c2a9b2eaf97a2d45368933b49d2b2
  11. Affected versionversion=bffcaad9afdfe45d7fc777397d3b83c1e3ebffe5 <b8b09dc2bf35a00d4e0556b5d6308c7b917ebda2
  12. Affected versionversion=d52fa1fa7440676b8c238037a050ab008c22737f
  13. Affected versionversion=f338ced0473849c9f6ed0b77ca99f1aab5826787

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=497f99b26fffdc5635706d1b4811f1ed8ee21a5b; version=5e1c1d22268ae710c238342c8030c21daf298168; version=6.1.176 <6.2; version=6.12.94 <6.13; version=6.18.24 <6.19; version=6.19.14 <6.20; version=6.6.143 <6.7; version=7.0; version=9e1196d27ef496f404c76f7a9d03761142d991c4; version=bffcaad9afdfe45d7fc777397d3b83c1e3ebffe5 <7ec786f4230c2a9b2eaf97a2d45368933b49d2b2; version=bffcaad9afdfe45d7fc777397d3b83c1e3ebffe5 <b8b09dc2bf35a00d4e0556b5d6308c7b917ebda2; version=d52fa1fa7440676b8c238037a050ab008c22737f; version=f338ced0473849c9f6ed0b77ca99f1aab5826787

Published CVSS scores

No CVSS assessment is available in this record.

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)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo