{"id":"CVE-2026-99126","aliases":[],"title":"s390/ctcm: Prevent XID null dereference","titleSource":"Linux","descriptionSource":"Linux","products":[{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"293d984f0e3604c04dcdbf00117ddc1e5d4b1909","status":"affected","lessThan":"34fa3607b7604b3052b19cec8b0ad644818cdd2a","versionType":"git"},{"version":"293d984f0e3604c04dcdbf00117ddc1e5d4b1909","status":"affected","lessThan":"8a2f7a4ad1d81612fa65bfa4d392ba1bb2f5eeab","versionType":"git"},{"version":"293d984f0e3604c04dcdbf00117ddc1e5d4b1909","status":"affected","lessThan":"b264d8422779d69febce914efc47a92a85cc382c","versionType":"git"}],"defaultStatus":"unaffected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99126"},{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"2.6.26","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.26","versionType":"semver"},{"version":"6.18.59","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.13","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"defaultStatus":"affected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99126"}],"remediation":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\ns390/ctcm: Prevent XID null dereference\n\nThe mpc_validate_xid() function sets grp->saved_xid2->xid2_flag2 to 0x40\nto signal XID validation error. If peer XID is NULL or r/w channel\npairing mismatch happens, grp->saved_xid2 is never initialized. An\nattempt to set the flag in such case leads to NULL dereference.\n\nFix this by using the always available priv->xid->xid2_flag2 instead of\ngrp->saved_xid2->xid2_flag2 for validation errors.","severity":"unknown","score":null,"published":"2026-10-28T10:34:40.661Z","modified":"2026-10-28T10:34:40.661Z","withdrawn":false,"knownExploited":false,"affected":[],"references":["https://git.kernel.org/stable/c/34fa3607b7604b3052b19cec8b0ad644818cdd2a","https://git.kernel.org/stable/c/8a2f7a4ad1d81612fa65bfa4d392ba1bb2f5eeab","https://git.kernel.org/stable/c/b264d8422779d69febce914efc47a92a85cc382c"],"sources":[{"name":"CVE","id":"CVE-2026-99126","modified":"2026-10-28T10:34:40.661Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-99126"}],"assessments":[],"sourceAffected":[],"kev":{"status":"not-listed","checkedAt":"2026-10-28T20:05:31.497Z"},"coverage":[{"source":"NVD","status":"not-checked"},{"source":"GHSA","status":"not-checked"},{"source":"EUVD","status":"not-checked"},{"source":"EPSS","status":"not-checked"}],"evidence":[]}