CVE-2026-98306: Linux kernel · seg6: set IPSKB_L3SLAVE from IP6SKB_L3SLAVE on IPIP decapsulation
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in f8fb4738ccef5f9d107845b05734a56352747b1a : update Linux kernel when convenient.
Data as of 26 Oct 2026, 16:39 UTC
Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in f8fb4738ccef5f9d107845b05734a56352747b1a, e4d7c52f15f572608374947c6c802052e1a2fc82, ddf60220c925b54a1714c4722fdbdb12833232d0 +5
Exploitation evidence
Disclosed: evidence found.
CVE published 6 Oct 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 and has been applied in multiple Linux kernel commits. Users should update to a kernel version including the fix identified by commits such as f8fb4738ccef5f9d107845b05734a56352747b1a and others listed. No additional mitigation is required once updated, as the patch ensures correct flag setting and socket lookup behavior.
Description
A vulnerability in the Linux kernel's seg6 module involves improper setting of the IPSKB_L3SLAVE flag during IPIP decapsulation. This causes socket lookup inconsistencies for packets arriving on interfaces enslaved to a VRF, leading to unbound UDP or TCP sockets not receiving decapsulated packets as expected. The issue contradicts documented VRF socket scope behavior and has been fixed by ensuring IPSKB_L3SLAVE is set correctly during decapsulation.
References
- git.kernel.org/stable/c/1d9f5c78903dd25a3556229eb716dd465c5f3573 (opens in a new tab)
- git.kernel.org/stable/c/72f410616000d21a0a6ec6c93a60301b9c92e95c (opens in a new tab)
- git.kernel.org/stable/c/e4d7c52f15f572608374947c6c802052e1a2fc82 (opens in a new tab)
- git.kernel.org/stable/c/5130afa025c95faa621adf8bac525baeb2b290d2 (opens in a new tab)
- git.kernel.org/stable/c/f8fb4738ccef5f9d107845b05734a56352747b1a (opens in a new tab)
- git.kernel.org/stable/c/ddf60220c925b54a1714c4722fdbdb12833232d0 (opens in a new tab)
- git.kernel.org/stable/c/8c16e1ccc082a3763dfc6bc2d3f658c1a6336f9d (opens in a new tab)
- git.kernel.org/stable/c/7616242a2b37883f7322aaa1d2bd6cd0fed28315 (opens in a new tab)