CVE-2026-63917
In the Linux kernel, the following vulnerability has been resolved: ip6: vti: Use ip6_tnl.net in vti6_changelink(). ip netns add ns1 ip netns add ns2 ip -n ns1 link add vti6_test type vti6 remote ::1 local ::2 key 7 ip -n ns1 link set vti6_test netns…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.17%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
In the Linux kernel, the following vulnerability has been resolved: ip6: vti: Use ip6_tnl.net in vti6_changelink(). ip netns add ns1 ip netns add ns2 ip -n ns1 link add vti6_test type vti6 remote ::1 local ::2 key 7 ip -n ns1 link set vti6_test netns ns2 ip -n ns2 link set vti6_test type vti6 remote ::3 local ::4 key 9 ip netns del ns2 ip netns del ns1 [ 132.495484] ------------[ cut here ]------------ [ 132.497609] kernel BUG at net/core/dev.c:12376! Commit 61220ab34948 ("vti6: Enable namespace changing") dropped NETIF_F_NETNS_LOCAL from vti6 devices. A vti6 tunnel can then move through IFLA_NET_NS_FD. After the move dev_net(dev) points at the new netns while t->net stays at the creation netns. vti6_changelink() and vti6_update() still use dev_net(dev) and dev_net(t->dev). They unlink from one per netns hash and relink into another. The creation netns is left with a stale entry. cleanup_net() of that netns later walks freed memory. Reachable from an unprivileged user namespace (unshare --user --map-root-user --net). Cross tenant scope on container hosts.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- EPSS
- 0.17% probability · 6th percentile
- CISA KEV
- Not listed
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/0cdce7618464f7fb06f461e8f4ad575cb1d570f4
- https://git.kernel.org/stable/c/11b326fb0a374f4654f9be22d0f0f7abd9f7d3fe
- https://git.kernel.org/stable/c/225b467e3b631f38be22e4b38062a1fed02fdd21
- https://git.kernel.org/stable/c/d9c5eecdb3c740e65038651db7c686b10d76d1bc
- https://git.kernel.org/stable/c/ee1778ba0f5cb53be771f97017d01eb356c797bf
- https://git.kernel.org/stable/c/f1e89a943ee574d0f2f16246eb3f2d7330fdeb03
- https://git.kernel.org/stable/c/f5c68875e25f331e497ddfbe81e2d8163a87f136
- https://git.kernel.org/stable/c/fc32be9ac2788524c6b24efd681cce7a6e731a92
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.