{"id":"CVE-2026-98403","title":"In the Linux kernel, the following vulnerability has been resolved:\n\ns390/boot: Avoid IPL parameter append past command line\n\nA command line may occupy all but the terminating byte of\nCOMMAND_LINE_SIZE","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ns390/boot: Avoid IPL parameter append past command line\n\nA command line may occupy all but the terminating byte of\nCOMMAND_LINE_SIZE. In that case append_ipl_block_parm…","severity":"high","published":"2026-10-14","updated":"2026-10-14","sourceUpdated":"2026-10-14T14:17:51.383","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-98403","references":[{"url":"https://git.kernel.org/stable/c/73eec5a0d55916d7e1115f5d03a7ffc06d6215cf","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8d11bfec8666f8409fac9072e9c25b691d3e30ac","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/af9866021a00ab9eeacf0c33ee73f3d134b4ed70","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d76181dfabdaa720703167393704efacba343442","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98403.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-98403"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2552209"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98403"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98403"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98403.mbox"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"ingestedAt":"2026-10-14T15:36:13.981Z","vendor":"Linux","product":"Linux","affected":["Linux >= 5ecb2da660ab8eddafe059a6a8a708465db89ca2 < af9866021a00ab9eeacf0c33ee73f3d134b4ed70","Linux >= 5ecb2da660ab8eddafe059a6a8a708465db89ca2 < 73eec5a0d55916d7e1115f5d03a7ffc06d6215cf","Linux >= 5ecb2da660ab8eddafe059a6a8a708465db89ca2 < 8d11bfec8666f8409fac9072e9c25b691d3e30ac","Linux >= 5ecb2da660ab8eddafe059a6a8a708465db89ca2 < d76181dfabdaa720703167393704efacba343442","Linux 5.16"],"cvss":7,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"vendor","cwe":["CWE-787"],"epss":0.00206,"epssPercentile":0.10478,"slug":"CVE-2026-98403","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ns390/boot: Avoid IPL parameter append past command line\n\nA command line may occupy all but the terminating byte of\nCOMMAND_LINE_SIZE. In that case append_ipl_block_parm() passes a zero size\nto the IPL parameter conversion helpers and points the destination one\nbyte past early_command_line. The helpers subtract one from the unsigned\nsize and write the converted parameter outside the command line buffer.\n\nConvert the IPL parameter in the command line parsing buffer first. A\nparameter beginning with '=' can then replace the existing command line\nregardless of its length, while other parameters are appended only when\nspace remains.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98403.json)","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":222948,"id":"CVE-2026-98403","ts":1792151736183,"field":"cvss","old":null,"new":"7"},{"seq":222947,"id":"CVE-2026-98403","ts":1792151736183,"field":"severity","old":"none","new":"high"}]}