{"id":"CVE-2026-98403","state":"PUBLISHED","title":"s390/boot: Avoid IPL parameter append past command line","description":"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() 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.","publishedAt":"2026-10-14T13:26:02.916Z","updatedAt":"2026-10-19T09:18:56.682Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5ecb2da660ab8eddafe059a6a8a708465db89ca2","status":"affected","lessThan":"af9866021a00ab9eeacf0c33ee73f3d134b4ed70","versionType":"git"},{"version":"5ecb2da660ab8eddafe059a6a8a708465db89ca2","status":"affected","lessThan":"73eec5a0d55916d7e1115f5d03a7ffc06d6215cf","versionType":"git"},{"version":"5ecb2da660ab8eddafe059a6a8a708465db89ca2","status":"affected","lessThan":"8d11bfec8666f8409fac9072e9c25b691d3e30ac","versionType":"git"},{"version":"5ecb2da660ab8eddafe059a6a8a708465db89ca2","status":"affected","lessThan":"d76181dfabdaa720703167393704efacba343442","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/s390/boot/ipl_parm.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.16","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/s390/boot/ipl_parm.c"]}],"references":["https://git.kernel.org/stable/c/af9866021a00ab9eeacf0c33ee73f3d134b4ed70","https://git.kernel.org/stable/c/73eec5a0d55916d7e1115f5d03a7ffc06d6215cf","https://git.kernel.org/stable/c/8d11bfec8666f8409fac9072e9c25b691d3e30ac","https://git.kernel.org/stable/c/d76181dfabdaa720703167393704efacba343442"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98403.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98403","state":"PUBLISHED","datePublished":"2026-10-14T13:26:02.916Z","dateUpdated":"2026-10-19T09:18:56.682Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.347Z"},"containers":{"cna":{"title":"s390/boot: Avoid IPL parameter append past command line","descriptions":[{"lang":"en","value":"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() 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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5ecb2da660ab8eddafe059a6a8a708465db89ca2","status":"affected","lessThan":"af9866021a00ab9eeacf0c33ee73f3d134b4ed70","versionType":"git"},{"version":"5ecb2da660ab8eddafe059a6a8a708465db89ca2","status":"affected","lessThan":"73eec5a0d55916d7e1115f5d03a7ffc06d6215cf","versionType":"git"},{"version":"5ecb2da660ab8eddafe059a6a8a708465db89ca2","status":"affected","lessThan":"8d11bfec8666f8409fac9072e9c25b691d3e30ac","versionType":"git"},{"version":"5ecb2da660ab8eddafe059a6a8a708465db89ca2","status":"affected","lessThan":"d76181dfabdaa720703167393704efacba343442","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/s390/boot/ipl_parm.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.16","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/s390/boot/ipl_parm.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/af9866021a00ab9eeacf0c33ee73f3d134b4ed70"},{"url":"https://git.kernel.org/stable/c/73eec5a0d55916d7e1115f5d03a7ffc06d6215cf"},{"url":"https://git.kernel.org/stable/c/8d11bfec8666f8409fac9072e9c25b691d3e30ac"},{"url":"https://git.kernel.org/stable/c/d76181dfabdaa720703167393704efacba343442"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:18:56.682Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"6.12.112"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"6.18.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"7.2.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}