CVE-2026-46120: Linux kernel · ip6_gre: Use cached t->net in ip6erspan_changelink().
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in eca62bb0569de4d43a4dac06a2092a9d4ca1d702 : 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 eca62bb0569de4d43a4dac06a2092a9d4ca1d702, e70cfb40c3a99b232cd42c6a6a10f0d8e039dc82, cf7fc624329e76c6394653d12353e1d033adea91 +6
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 28 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 to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
Description
In the Linux kernel, the following vulnerability has been resolved: ip6_gre: Use cached t->net in ip6erspan_changelink(). After commit 5e72ce3e3980 ("net: ipv6: Use link netns in newlink() of rtnl_link_ops"), ip6erspan_newlink() correctly resolves the per-netns ip6gre hash via link_net. ip6erspan_changelink() was not converted in that series and still uses dev_net(dev), which diverges from the device's creation netns after IFLA_NET_NS_FD migration. This re-inserts the tunnel into the wrong per-netns hash. The original netns keeps a stale entry. When that netns is later destroyed, ip6gre_exit_rtnl_net() walks the stale entry, producing a slab-use-after-free reported by KASAN, followed by a kernel BUG at net/core/dev.c (LIST_POISON1) in unregister_netdevice_many_notify(). Reachable from an unprivileged user namespace (unshare --user --map-root-user --net). ip6gre_changelink() earlier in the same file already uses the cached t->net; only ip6erspan_changelink() has the wrong shape.
References
- git.kernel.org/stable/c/7bd0f2b162b426b343a114e1b329f0d8d14fdc6e (opens in a new tab)
- git.kernel.org/stable/c/01b71ff2857d3598337de11e7840a8e3ff21553c (opens in a new tab)
- git.kernel.org/stable/c/0fcf6731706f73494245a9c0d64f93bebf95bb51 (opens in a new tab)
- git.kernel.org/stable/c/eca62bb0569de4d43a4dac06a2092a9d4ca1d702 (opens in a new tab)
- git.kernel.org/stable/c/311fdd26eb4443d43b909cc67a10f3a5fd1b21b2 (opens in a new tab)
- git.kernel.org/stable/c/e70cfb40c3a99b232cd42c6a6a10f0d8e039dc82 (opens in a new tab)
- git.kernel.org/stable/c/cf7fc624329e76c6394653d12353e1d033adea91 (opens in a new tab)
- git.kernel.org/stable/c/1d324c2f43f70c965f25c58cc3611c779adbe47e (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)