CVE-2026-68432

vxlan: require CAP_NET_ADMIN in the device netns for changelink

State: Published
Severity: 8.8 High
Published: Aug 12, 2026
Updated: Oct 19, 2026
Reserved: Jul 30, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

vxlan: require CAP_NET_ADMIN in the device netns for changelink

A tunnel changelink() operates on at most two netns, dev_net(dev) and the sticky underlay netns vxlan->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 vxlan->net can rewrite a vxlan device whose underlay lives in vxlan->net.

vxlan_changelink() validates and applies the new configuration against vxlan->net (vxlan_config_validate(vxlan->net, ...)) and can reopen the underlay socket in that netns, so the same reasoning as the tunnel changelink series applies here.

Gate vxlan_changelink() with rtnl_dev_link_net_capable(), at the top of the op before any attribute is parsed, matching ipgre_changelink() and the rest of the "require CAP_NET_ADMIN in the device netns for changelink" series.

Found by 0sec automated security-research tooling (https://0sec.ai).

Scores

CVSS	Score	Vector	Source
3.1	8.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H	Linux

Weaknesses

CWE-863 Incorrect Authorization

Affected Products

Product	Versions
LinuxLinux	8bcdc4f3a20be949df54b67e5ae2734daabb5792 to before b95a8743e58f7efed5ddc4cb73829b66f17feab0Affected 8bcdc4f3a20be949df54b67e5ae2734daabb5792 to before 7465ade989ba84adc2bfa58bad3ca25d249f0f7aAffected 8bcdc4f3a20be949df54b67e5ae2734daabb5792 to before 0aa580a8bbbed2507b4582a1f0ef581d480d06edAffected 8bcdc4f3a20be949df54b67e5ae2734daabb5792 to before b3793d7dccb192ffff29894d11824db6251acdd5Affected 8bcdc4f3a20be949df54b67e5ae2734daabb5792 to before 32d10c46bfde3e9b274e9e1bd6399d0ebea8f60fAffected 8bcdc4f3a20be949df54b67e5ae2734daabb5792 to before 730c7e5fea7f06e0cdf21c547222ec93234fd1d6Affected 8bcdc4f3a20be949df54b67e5ae2734daabb5792 to before e8ad0d311e225939a9a6c745d6cc384c7364ec87Affected 8bcdc4f3a20be949df54b67e5ae2734daabb5792 to before 3a61bd9637f3d929aa846e4eb3d98b48c26fcb0eAffected
LinuxLinux	4.11Affected before 4.11Not affected 5.10.265 through 5.10.Not affected 5.15.216 through 5.15.Not affected 6.1.183 through 6.1.Not affected 6.6.148 through 6.6.Not affected 6.12.101 through 6.12.Not affected 6.18.42 through 6.18.Not affected 7.1.6 through 7.1.*Not affected 7.2 and laterNot affected

Product

Versions

LinuxLinux

8bcdc4f3a20be949df54b67e5ae2734daabb5792 to before b95a8743e58f7efed5ddc4cb73829b66f17feab0Affected
8bcdc4f3a20be949df54b67e5ae2734daabb5792 to before 7465ade989ba84adc2bfa58bad3ca25d249f0f7aAffected
8bcdc4f3a20be949df54b67e5ae2734daabb5792 to before 0aa580a8bbbed2507b4582a1f0ef581d480d06edAffected
8bcdc4f3a20be949df54b67e5ae2734daabb5792 to before b3793d7dccb192ffff29894d11824db6251acdd5Affected
8bcdc4f3a20be949df54b67e5ae2734daabb5792 to before 32d10c46bfde3e9b274e9e1bd6399d0ebea8f60fAffected
8bcdc4f3a20be949df54b67e5ae2734daabb5792 to before 730c7e5fea7f06e0cdf21c547222ec93234fd1d6Affected
8bcdc4f3a20be949df54b67e5ae2734daabb5792 to before e8ad0d311e225939a9a6c745d6cc384c7364ec87Affected
8bcdc4f3a20be949df54b67e5ae2734daabb5792 to before 3a61bd9637f3d929aa846e4eb3d98b48c26fcb0eAffected

LinuxLinux

4.11Affected
before 4.11Not affected
5.10.265 through 5.10.*Not affected
5.15.216 through 5.15.*Not affected
6.1.183 through 6.1.*Not affected
6.6.148 through 6.6.*Not affected
6.12.101 through 6.12.*Not affected
6.18.42 through 6.18.*Not affected
7.1.6 through 7.1.*Not affected
7.2 and laterNot affected

References

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