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VulnerabilityPublished Updated

CVE-2026-46120: Linux kernel · ip6_gre: Use cached t->net in ip6erspan_changelink().

Affects Linux kernelSource CVE Database V5

0

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

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
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:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 28 May 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
LinuxLinuxAffected
  • >=4.16.12 <4.17
Fixed in
  • eca62bb0569de4d43a4dac06a2092a9d4ca1d702
  • e70cfb40c3a99b232cd42c6a6a10f0d8e039dc82
  • cf7fc624329e76c6394653d12353e1d033adea91
  • 311fdd26eb4443d43b909cc67a10f3a5fd1b21b2
  • 7bd0f2b162b426b343a114e1b329f0d8d14fdc6e
  • 4.17
  • 1d324c2f43f70c965f25c58cc3611c779adbe47e
  • 01b71ff2857d3598337de11e7840a8e3ff21553c
  • 0fcf6731706f73494245a9c0d64f93bebf95bb51
LinuxLinuxAffected
  • =4.17
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

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