Vulnerability in Linux

[ Description ]Official description

In the Linux kernel, the following vulnerability has been resolved: s390/boot: Avoid IPL parameter append past command line A command line may occupy all but the terminating byte of COMMAND_LINE_SIZE. In that case append_ipl_block_parm() passes a zero size to the IPL parameter conversion helpers and points the destination one byte past early_command_line. The helpers subtract one from the unsigned size and write the converted parameter outside the command line buffer. Convert the IPL parameter in the command line parsing buffer first. A parameter beginning with '=' can then replace the existing command line regardless of its length, while other parameters are appended only when space remains.

[ 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-Bund14 Oct 2026WID-SEC-2026-3951

  Linux Kernel: Multiple vulnerabilities Translated from German

  CVE-2026-98426CVE-2026-98416CVE-2026-98393+43 more CVEs

[ References ]References

• git.kernel.org/stable/c/73eec5a0d55916d7e1115f5d03a7ffc06d6215cf
• git.kernel.org/stable/c/8d11bfec8666f8409fac9072e9c25b691d3e30ac
• git.kernel.org/stable/c/af9866021a00ab9eeacf0c33ee73f3d134b4ed70
• git.kernel.org/stable/c/d76181dfabdaa720703167393704efacba343442