{"id":"CVE-2026-63923","title":"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 qu…","summary":"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 qu…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","published":"2026-07-19","updated":"2026-08-03","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-63923","references":[{"url":"https://git.kernel.org/stable/c/2156a29aecfffa2eb7c558255690084efbe9f3b0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4467fa514482bbce82f73788943c815f3d126ab3","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/68be0260e2a02ff9b18a8678d5f8d1715fa20138","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63923.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-63923"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2502418"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63923"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63923"},{"url":"https://lore.kernel.org/linux-cve-announce/2026071948-CVE-2026-63923-8d3f@gregkh/T"},{"url":"https://access.redhat.com/errata/RHSA-2026:67470"},{"url":"https://access.redhat.com/errata/RHSA-2026:68507"}],"tags":["nvd","csaf","vex","red-hat"],"epss":0.00166,"epssPercentile":0.05157,"ingestedAt":"2026-08-03T10:24:20.562Z","vendor":"Red Hat","product":"Red Hat Enterprise Linux BaseOS (v. 9)","affected":["enterprise_linux 10","enterprise_linux 9","enterprise_linux_appstream_v_9","enterprise_linux_baseos_v_9","enterprise_linux_codeready_linux_builder_v_9","enterprise_linux_real_time_for_nfv_v_9","enterprise_linux_real_time_v_9"],"patched":["enterprise_linux_appstream_v_9","enterprise_linux_baseos_v_9","enterprise_linux_codeready_linux_builder_v_9","enterprise_linux_real_time_for_nfv_v_9","enterprise_linux_real_time_v_9"],"cwe":["CWE-787"],"scores":{"nvd":8.8,"vendor":7},"slug":"CVE-2026-63923","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:67470** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2026-09-15 · [advisory](https://access.redhat.com/errata/RHSA-2026:67470)\n- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 9 · updated 2026-09-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63923.json)\n- **RHSA-2026:68507** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), Red Hat Enterprise Linux Real Time (v. 10) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68507)","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}