Vulnerability in Linux

[ Description ]Official description

In the Linux kernel, the following vulnerability has been resolved: netfilter: flowtable: hold reference on ct until flow is released nf_ct_put() releases the ct->ext area inmediately, the rcu typesafe semantics also allow to refer to the wrong conntrack from the flowtable datapath. Hold reference on ct until flow is released after rcu grace period. Add rcu_barrier() on module exit path, to ensure pending flow entries are release before module goes away.

[ 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-Bund5 Oct 2026WID-SEC-2026-3743

  Linux Kernel: Multiple vulnerabilities Translated from German

  Risk mediumCVE-2026-98221CVE-2026-98181CVE-2026-98248+204 more CVEs

[ References ]References

• git.kernel.org/stable/c/12c1ac230f4ca16e0017b62a963ab75e0b48074f
• git.kernel.org/stable/c/61c6688be282277c6e91ab286a7acd0ae8681ac6
• git.kernel.org/stable/c/8274cdc5f9c57e17ed77fc4ba76212536c840f25
• git.kernel.org/stable/c/93ff1594be1aad4da364462dd8db050ebcfda2de
• git.kernel.org/stable/c/a43cd2b67b91e943273c913237a7a88c50cdcfbc
• git.kernel.org/stable/c/d9e6175a3ee48209ee65f294fc567b4e16b29b74
• git.kernel.org/stable/c/e75a9fa1d44bcbd66ea02e8781bcca6ea4076e0d
• git.kernel.org/stable/c/eed6997e8dc40593a539fcc722e7ed51b18db86c