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VulnerabilityPublished Updated

CVE-2026-23270: Linux kernel · Use After Free

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in fb3c380a54e33d1fd272cc342faa906d787d7ef1 : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:30 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in fb3c380a54e33d1fd272cc342faa906d787d7ef1, bc4e5bb529823a09f02dbe96169de679a9db26e0, 524ce8b4ea8f64900b6c52b6a28df74f6bc0801e +8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 18 Mar 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • >=5.15.148 <5.15.203
  • >=6.1.75 <6.1.167
  • >=6.6.14 <6.6.130
  • >=6.7.2 <6.8
Fixed in
  • fb3c380a54e33d1fd272cc342faa906d787d7ef1
  • bc4e5bb529823a09f02dbe96169de679a9db26e0
  • 524ce8b4ea8f64900b6c52b6a28df74f6bc0801e
  • 380ad8b7c65ea7aa10ef2258297079ed5ac1f5b6
  • 11cb63b0d1a0685e0831ae3c77223e002ef18189
  • 9deda0fcda5c1f388c5e279541850b71a2ccfcf4
  • 6.8
  • 6.6.130
  • 6.1.167
  • 5a110ddcc99bda77a28598b3555fe009eaab3828
  • 5.15.203
LinuxLinuxAffected
  • =6.8
Fixed in–

AI-suggested

A fix is available and has been applied in the Linux kernel versions identified by the fixed commits and version numbers. Users should upgrade to these fixed versions to mitigate the vulnerability. No additional mitigation steps are indicated beyond applying the official patches.

Description

CVE-2026-23270 is a high-severity vulnerability in the Linux kernel's network scheduler (net/sched) subsystem. It involves improper binding of the act_ct action to queueing disciplines (qdiscs) other than clsact/ingress and shared blocks, which can lead to use-after-free conditions during packet defragmentation. The flaw was addressed by restricting act_ct binding to only clsact/ingress qdiscs and shared blocks, preventing unsafe usage on egress paths. This vulnerability affects multiple Linux kernel versions prior to the fixed releases.

References

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