High 8.8Published Jul 19, 2026

CVE-2026-63829net: ip_gre: require CAP_NET_ADMIN in the device netns for changelink

Updated under an hour ago (Oct 28, 2026, 3:10 AM ET)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: net: ip_gre: require CAP_NET_ADMIN in the device netns for changelink A tunnel changelink() operates on at most two netns, dev_net(dev) and the tunnel link netns t->net. They differ once the device is created in or moved to a netns other than the one the request runs in. The rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a caller privileged there but not in t->net can rewrite a tunnel that lives in t->net. Add rtnl_dev_link_net_capable() next to rtnl_get_net_ns_capable() in net/core/rtnetlink.c. It requires CAP_NET_ADMIN in the link netns and is skipped when the link netns is dev_net(dev), where the rtnl path already checked it. The other patches in this series use the same helper. Gate ipgre_changelink() and erspan_changelink() with it, at the top of the op before any attribute is parsed, because the parsers update live tunnel fields first. ipgre_netlink_parms() sets t->collect_md before ip_tunnel_changelink() runs. Commit 8b484efd5cb4 ("ip6: vti: Use ip6_tnl.net in vti6_siocdevprivate().") added the same check on the ioctl path. This adds it on RTM_NEWLINK.

CVSS: 8.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Weakness (CWE): CWE-862
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: Oct 19, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from b57708add31494175be741ed3fd24023b50c3423 before 19275943d8fe903eb7b9aa53e380e41efd042ada; from b57708add31494175be741ed3fd24023b50c3423 before 866b0f5ae599490bd496fd84581c68ac8b94e6af; from b57708add31494175be741ed3fd24023b50c3423 before 92b766fc55156e0da2ecd0c2302c971118f8a229; from b57708add31494175be741ed3fd24023b50c3423 before e54c05ed3d9c28733fb9e5837219aca3691defa3; from b57708add31494175be741ed3fd24023b50c3423 before 9831bc9ecb402957810c2045c663fbfe9b09e296; from b57708add31494175be741ed3fd24023b50c3423 before 1697957eb0971d420dde42862b88eb43506a1105; from b57708add31494175be741ed3fd24023b50c3423 before 47b5d3d506609b08b2e1f7c14f0b681a1953d572; from b57708add31494175be741ed3fd24023b50c3423 before 8165f7ff57d9667d2bb477ef6af83ede7fed4ad7	CNA record
linux linux_kernel linux:linux_kernel	from 3.16 before 5.10.261; from 5.11 before 5.15.212; from 5.16 before 6.1.178; from 6.2 before 6.6.145; from 6.7 before 6.12.95; from 6.13 before 6.18.38; from 6.19 before 7.1.3	NVD

References

References

https://git.kernel.org/stable/c/19275943d8fe903eb7b9aa53e380e41efd042ada	patch
https://git.kernel.org/stable/c/866b0f5ae599490bd496fd84581c68ac8b94e6af	patch
https://git.kernel.org/stable/c/92b766fc55156e0da2ecd0c2302c971118f8a229	patch
https://git.kernel.org/stable/c/e54c05ed3d9c28733fb9e5837219aca3691defa3	patch
https://git.kernel.org/stable/c/9831bc9ecb402957810c2045c663fbfe9b09e296	patch
https://git.kernel.org/stable/c/1697957eb0971d420dde42862b88eb43506a1105	patch
https://git.kernel.org/stable/c/47b5d3d506609b08b2e1f7c14f0b681a1953d572	patch
https://git.kernel.org/stable/c/8165f7ff57d9667d2bb477ef6af83ede7fed4ad7	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.