{"id":"CVE-2026-63923","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-63923","generatedAt":"2026-10-28T00:28:56.495Z","title":"In the Linux kernel, the following vulnerability has been resolved: octeontx2-af: validate body pcifunc in rvu_mbox_handler_rep_event_notify rvu_mbox_handler_rep_event_notify() in drivers/net/ethernet/marvell/ octeontx2/af/rvu_rep.c queues a…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nocteontx2-af: validate body pcifunc in rvu_mbox_handler_rep_event_notify\n\nrvu_mbox_handler_rep_event_notify() in drivers/net/ethernet/marvell/\nocteontx2/af/rvu_rep.c queues a sender-controlled REP_EVENT_NOTIFY\nrequest body verbatim, and rvu_rep_up_notify() then forwards\nevent->pcifunc (the nested body field, distinct from the\nAF-normalised header pcifunc) into rvu_get_pfvf(), rvu_get_pf() and\nthe AF->PF mailbox device index without any bounds check.\n\nA VF attached to a PF that has been put into switchdev\nrepresentor mode reaches this path: the VF mailbox handler\notx2_pfvf_mbox_handler() forwards every message id including\nMBOX_MSG_REP_EVENT_NOTIFY to AF without an allowlist, and the AF\ndispatcher rewrites only msg->pcifunc, leaving struct\nrep_event::pcifunc attacker-controlled.  The sibling\nrvu_mbox_handler_esw_cfg() refuses requests whose header pcifunc\nis not rvu->rep_pcifunc; this handler has no equivalent gate.\n\nAn out-of-range body pcifunc selects an &rvu->pf[]/&rvu->hwvf[]\nelement past the allocated array and, for RVU_EVENT_MAC_ADDR_CHANGE,\nturns into a six-byte attacker-chosen OOB ether_addr_copy() target\ninside the queued worker; KASAN reports a slab-out-of-bounds write\nin rvu_rep_wq_handler.\n\nReject malformed requests at the handler entry by gating on\nis_pf_func_valid(), which is already the canonical PF/VF range check\nin this driver; expose it via rvu.h so callers in rvu_rep.c can use\nit instead of open-coding the same range arithmetic.","published":"2026-07-19T16:17:11.000Z","lastModified":"2026-10-27T12:58:37.000Z","status":"Analyzed","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"},"cwe":["CWE-787"],"affected":["linux/linux kernel"],"epss":{"score":0.00173,"percentile":0.0672,"date":"2026-10-26","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 (0.17%). 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/2156a29aecfffa2eb7c558255690084efbe9f3b0","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4467fa514482bbce82f73788943c815f3d126ab3","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/68be0260e2a02ff9b18a8678d5f8d1715fa20138","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-63923","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."}