Vulnerability in Linux

[ Why it matters ]Priority signals

• Critical severity: CVSS 9.8

[ Description ]Official description

In the Linux kernel, the following vulnerability has been resolved: RDMA/siw: Bound fragmented header copies by the remaining length siw_get_hdr() can receive an extended DDP/RDMAP header across more than one TCP callback. The first callback may receive most of the header, while the next one still limits the copy to hdrlen - MIN_DDP_HDR instead of the number of missing bytes. This makes the destination move past the end of the header and overwrite the receive state, including fpdu_part_rcvd. A later callback can then use a negative fpdu_part_rcvd value as a copy offset, which creates an OOB write. Use the number of header bytes already received when calculating the next copy length.

[ 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/262dcd809723723ed8a4e05437ec7e9c21a8f17e
• git.kernel.org/stable/c/2c6fbcf4bfac0b2b186acc8d91154c0fa24468a7
• git.kernel.org/stable/c/8628f8ebf41669302513fb3f0bf0eba38b226742
• git.kernel.org/stable/c/9ff797e516dbc1ecb73701ec4c24055712d44411
• git.kernel.org/stable/c/af9f5b474a260ad23ffb9793d716a5e3bbce3b48
• git.kernel.org/stable/c/b72dcfb9bf1f0f0147cda03dc59e4002a315067f
• git.kernel.org/stable/c/e6bdfdf3bcb02d0d626a45e8c98b7e63d2fddf9d
• git.kernel.org/stable/c/eb4d7a946970469b3ab0c762432bf161d5b0836c