CVE-2026-23449: Linux kernel · net/sched: teql: Fix double-free in teql_master_xmit
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in e9c66d3e7d8557b3308e55c613aa07254fe97611 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:18 UTC
- 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 e9c66d3e7d8557b3308e55c613aa07254fe97611, afbc79a7770b230a9f24bd39271209d6b3682c5f, 66360460cab63c248ca5b1070a01c0c29133b960 +3
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 3 Apr 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
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
AI-suggested
A fix is available in the Linux kernel as indicated by multiple fixed commit versions. Users and administrators should update to a Linux kernel version that includes these fixes. No additional mitigation steps are indicated or required beyond applying the official patch.
Description
CVE-2026-23449 is a high-severity vulnerability in the Linux kernel's TEQL network scheduler. It involves a double-free bug in the teql_master_xmit function, which can cause kernel crashes due to improper handling of lockless Qdisc roots. The flaw arises from not using the seq_lock when calling qdisc_reset, leading to race conditions and memory corruption.
References
- git.kernel.org/stable/c/4e8ebc4c18ea8213d28e6cb867d18fcc67daca21 (opens in a new tab)
- git.kernel.org/stable/c/21c89a0a8de7eadad8d385645a95b3233f23130e (opens in a new tab)
- git.kernel.org/stable/c/afbc79a7770b230a9f24bd39271209d6b3682c5f (opens in a new tab)
- git.kernel.org/stable/c/e9c66d3e7d8557b3308e55c613aa07254fe97611 (opens in a new tab)
- git.kernel.org/stable/c/4a233447b941db451ea5f5a0942cffd0f7f7eaae (opens in a new tab)
- git.kernel.org/stable/c/66360460cab63c248ca5b1070a01c0c29133b960 (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)