Vulnerability in Linux

[ Description ]Official description

In the Linux kernel, the following vulnerability has been resolved: ip_gre: Reject enabling collect metadata through changelink ipgre_netlink_parms() can enable collect_md on an existing GRE, GRETAP or ERSPAN device. Unlike newlink, changelink does not enforce metadata tunnel uniqueness. Converting a non-metadata device can therefore replace the metadata receive entry for another device of the same type in the same netns. Deleting either device then clears the shared entry, breaking metadata receive lookup for the surviving device. If parameter validation fails after collect_md is set, deleting the modified device can also clear an entry it never owned. Reject enabling metadata mode in both changelink callbacks before any encapsulation or tunnel parameters are modified. Allow requests that repeat the metadata attribute on an existing metadata device.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund18 Oct 2026WID-SEC-2026-4019

  Linux Kernel: Multiple vulnerabilities Translated from German

  CVE-2026-98866CVE-2026-98624CVE-2026-98745+326 more CVEs

[ References ]References

• git.kernel.org/stable/c/1dc759571f3df14891175fc52527f7624ba01322
• git.kernel.org/stable/c/2e54d53b65e296b4b4bdc2cdd3b2b58dfa8d8c5c
• git.kernel.org/stable/c/63c5e48d6f7f5722a48f63e13e961dc5302894ed
• git.kernel.org/stable/c/a3f315be9d30eeb6938d11fa17fd4b32d52f7c42
• git.kernel.org/stable/c/bdd41b96e814300c66222cf4e47ecb8aef995656
• git.kernel.org/stable/c/c80315da84998b69b8829785a174b0bf72a81992
• git.kernel.org/stable/c/cff8b520312e750ad38967c30128e1534cbf9484
• git.kernel.org/stable/c/da2e0cfbb620b199927a1e5b93b7cfde32083c7d