CVE-2026-23340: Linux kernel · Race Condition
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in dbd58b0730aa06ab6ad26079cf9a5b6b58e7e750 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:18 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% 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 dbd58b0730aa06ab6ad26079cf9a5b6b58e7e750, c69df4e0524f8de8e176ba389acd83e85f5f49d0, 8314944cc3bdeaa5a73e6f8a8cf0d94822e625cb +4
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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AI-suggested
A fix is available and has been applied in multiple Linux kernel commits. Users and administrators should update to a Linux kernel version that includes these fixes. No additional mitigation is required beyond applying the official patch.
Description
CVE-2026-23340 is a race condition vulnerability in the Linux kernel's network scheduler subsystem affecting lockless queuing disciplines (qdiscs). It occurs when shrinking the number of real transmit queues, where concurrent operations can lead to use-after-free (UAF) conditions. This flaw can cause kernel memory corruption and potentially impact system stability or security. The issue has been fixed in several Linux kernel commits.
References
- git.kernel.org/stable/c/5bb27ad54d12de67e457d7d251198e361bef835e (opens in a new tab)
- git.kernel.org/stable/c/7594467c49bfc2f4644dee0415ac2290db11fa0d (opens in a new tab)
- git.kernel.org/stable/c/dbd58b0730aa06ab6ad26079cf9a5b6b58e7e750 (opens in a new tab)
- git.kernel.org/stable/c/5bc4e69306ed7ae02232eb4c0b23ed621a26d504 (opens in a new tab)
- git.kernel.org/stable/c/8314944cc3bdeaa5a73e6f8a8cf0d94822e625cb (opens in a new tab)
- git.kernel.org/stable/c/c69df4e0524f8de8e176ba389acd83e85f5f49d0 (opens in a new tab)
- git.kernel.org/stable/c/7f083faf59d14c04e01ec05a7507f036c965acf8 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-082556.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-457936.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)