{"id":"CVE-2026-89783","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-89783","generatedAt":"2026-09-20T13:19:06.578Z","title":"In the Linux kernel, the following vulnerability has been resolved: xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full The depth check in xfrm6_input_addr() is off by one: if (1 + sp->len == XFRM_MAX_DEPTH) goto drop; ...…","description":"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->len == XFRM_MAX_DEPTH)\n          goto drop;\n  ...\n  sp->xvec[sp->len++] = x;\n\nxfrm_input() can leave sp->len == 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->len == XFRM_MAX_DEPTH; the check (1 + 6 == 6) is false, so\nsp->xvec[sp->len++] 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->len >= XFRM_MAX_DEPTH\", matching xfrm_input(). This also\nrestores one chain level the old check rejected at sp->len == 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]'","published":"2026-09-16T09:17:09.000Z","lastModified":"2026-09-16T15:18:09.000Z","status":"Received","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":[],"affected":[],"epss":{"score":0.00704,"percentile":0.5185,"date":"2026-09-19","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.70%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/0f679e0523ddfff3fb554336ceb874b0e51e9cd3","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/48996649222e95008cdb98cd58579e3fc8e5ee06","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5d9e3bf34fec9a5d237e4b7cef4a707bc2e091bc","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5f35a29a5eed3d80befd32050843ac88dea3d61a","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/68e8737fe8e72f085c608cff322b3d2de8340af1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8fe2c53fb81f5ad5be43af2ad09583f7c78b4b77","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/91fc387f63c00ddfb5221127a17bac97549a8343","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bdcda866c89f9a8b1acdabf02d26cde9fbe501d8","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89783","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}