{"id":"CVE-2026-89783","summary":"xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full\n\nThe depth check in xfrm6_input_addr() is off by one:\n\n  if (1 + sp-\u003elen == XFRM_MAX_DEPTH)\n          goto drop;\n  ...\n  sp-\u003exvec[sp-\u003elen++] = x;\n\nxfrm_input() can leave sp-\u003elen == XFRM_MAX_DEPTH, and the transport-mode\nreceive path re-enters IPv6 input via xfrm_trans_reinject() with that\nsecpath preserved. If the inner packet carries a destination-options HAO\noption or a type-2 routing header, xfrm6_input_addr() is called with\nsp-\u003elen == XFRM_MAX_DEPTH; the check (1 + 6 == 6) is false, so\nsp-\u003exvec[sp-\u003elen++] writes one slot past the 6-element xvec[]. The write\nstays within the sec_path allocation (invisible to KASAN); UBSAN_BOUNDS\nflags it and panics under panic_on_warn.\n\nUse \"sp-\u003elen \u003e= XFRM_MAX_DEPTH\", matching xfrm_input(). This also\nrestores one chain level the old check rejected at sp-\u003elen == 5.\n\n  UBSAN: array-index-out-of-bounds in net/ipv6/xfrm6_input.c:309:10\n  index 6 is out of range for type 'xfrm_state *[6]'","modified":"2026-09-18T03:48:32.458395933Z","published":"2026-09-16T08:48:21.761Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89783.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0f679e0523ddfff3fb554336ceb874b0e51e9cd3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/48996649222e95008cdb98cd58579e3fc8e5ee06"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5d9e3bf34fec9a5d237e4b7cef4a707bc2e091bc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5f35a29a5eed3d80befd32050843ac88dea3d61a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/68e8737fe8e72f085c608cff322b3d2de8340af1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8fe2c53fb81f5ad5be43af2ad09583f7c78b4b77"},{"type":"WEB","url":"https://git.kernel.org/stable/c/91fc387f63c00ddfb5221127a17bac97549a8343"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bdcda866c89f9a8b1acdabf02d26cde9fbe501d8"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89783.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89783"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"9473e1f631de339c50bde1e3bd09e1045fe90fd5"},{"fixed":"91fc387f63c00ddfb5221127a17bac97549a8343"},{"fixed":"68e8737fe8e72f085c608cff322b3d2de8340af1"},{"fixed":"8fe2c53fb81f5ad5be43af2ad09583f7c78b4b77"},{"fixed":"bdcda866c89f9a8b1acdabf02d26cde9fbe501d8"},{"fixed":"48996649222e95008cdb98cd58579e3fc8e5ee06"},{"fixed":"0f679e0523ddfff3fb554336ceb874b0e51e9cd3"},{"fixed":"5f35a29a5eed3d80befd32050843ac88dea3d61a"},{"fixed":"5d9e3bf34fec9a5d237e4b7cef4a707bc2e091bc"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89783.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.6.25"},{"fixed":"5.10.270"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.221"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.188"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.157"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.110"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.52"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89783.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}