CVE-2026-43042: Linux kernel · mpls: add seqcount to protect the platform_label{,s} pair
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.1 High · fixed in 629ec78ef8608d955ce217880cdc3e1873af3a15 : 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
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in 629ec78ef8608d955ce217880cdc3e1873af3a15, 8adc5b6fc876928d8c95555d30b66fa50b07421e, 5bb3caf0bbfb56f1a00d2af072ac3d8395a3b9ef +1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 1 May 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 Linux kernel to 629ec78ef8608d955ce217880cdc3e1873af3a15, 8adc5b6fc876928d8c95555d30b66fa50b07421e, 5bb3caf0bbfb56f1a00d2af072ac3d8395a3b9ef or 0d377825548fe598595b5a5fa4a309fb593d8fb4.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
Description
In the Linux kernel, the following vulnerability has been resolved: mpls: add seqcount to protect the platform_label{,s} pair The RCU-protected codepaths (mpls_forward, mpls_dump_routes) can have an inconsistent view of platform_labels vs platform_label in case of a concurrent resize (resize_platform_label_table, under platform_mutex). This can lead to OOB accesses. This patch adds a seqcount, so that we get a consistent snapshot. Note that mpls_label_ok is also susceptible to this, so the check against RTA_DST in rtm_to_route_config, done outside platform_mutex, is not sufficient. This value gets passed to mpls_label_ok once more in both mpls_route_add and mpls_route_del, so there is no issue, but that additional check must not be removed.
References
- git.kernel.org/stable/c/0d377825548fe598595b5a5fa4a309fb593d8fb4 (opens in a new tab)
- git.kernel.org/stable/c/8adc5b6fc876928d8c95555d30b66fa50b07421e (opens in a new tab)
- git.kernel.org/stable/c/5bb3caf0bbfb56f1a00d2af072ac3d8395a3b9ef (opens in a new tab)
- git.kernel.org/stable/c/629ec78ef8608d955ce217880cdc3e1873af3a15 (opens in a new tab)