CVE-2026-63923

HIGHPre-NVD 8.88.8
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-19. the CNA's CVSS baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:linux, epss, ghsa
Trending — 4 sources updated this week
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.8Exploit: None knownExposed: 0

A fix is available — apply it.

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 sender-controlled REP_EVENT_NOTIFY request body verbatim, and rvu_rep_up_notify() then forwards event->pcifunc (the nested body field, distinct from the AF-normalised header pcifunc) into rvu_get_pfvf(), rvu_get_pf() and the AF->PF mailbox device index without any bounds check.

A VF attached to a PF that has been put into switchdev representor mode reaches this path: the VF mailbox handler otx2_pfvf_mbox_handler() forwards every message id including MBOX_MSG_REP_EVENT_NOTIFY to AF without an allowlist, and the AF dispatcher rewrites only msg->pcifunc, leaving struct rep_event::pcifunc attacker-controlled. The sibling rvu_mbox_handler_esw_cfg() refuses requests whose header pcifunc is not rvu->rep_pcifunc; this handler has no equivalent gate.

An out-of-range body pcifunc selects an &rvu->pf[]/&rvu->hwvf[] element past the allocated array and, for RVU_EVENT_MAC_ADDR_CHANGE, turns into a six-byte attacker-chosen OOB ether_addr_copy() target inside the queued worker; KASAN reports a slab-out-of-bounds write in rvu_rep_wq_handler.

Reject malformed requests at the handler entry by gating on is_pf_func_valid(), which is already the canonical PF/VF range check in this driver; expose it via rvu.h so callers in rvu_rep.c can use it instead of open-coding the same range arithmetic.

CVSS v3
8.8
EG Score
8.8(medium)
EG Risk
44(Track)
EG Risk 44/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity88% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
6%
KEV
Not listed

Published

July 19, 2026

Last Modified

August 5, 2026

Advisory Details (2)

Auto-updated Jul 20, 2026
No patch confirmed yet.
generic

octeontx2-af: validate body pcifunc in rvu_mbox_handler_rep_event_notify - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/68be0260e2a02ff9b18a8678d5f8d1715fa20138
generic

octeontx2-af: validate body pcifunc in rvu_mbox_handler_rep_event_notify - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2156a29aecfffa2eb7c558255690084efbe9f3b0

Vendor Advisories for CVE-2026-63923(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(5)

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.0.9-1~bpo13+1 (138 versions)7.0.12-1

All Vendor Advisories

(5)

Data Freshness Timeline

(refreshed 31× in last 7d / 171× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 221 total refreshes for this CVE.

  1. 2026-08-30 02:57 UTCEG score recompute
  2. 2026-08-30 02:57 UTCVendor advisory
  3. 2026-08-30 02:57 UTCGHSA enrichment
  4. 2026-08-30 01:22 UTCEPSS rescore
  5. 2026-08-28 21:42 UTCEPSS rescore
  6. 2026-08-27 22:58 UTCEG score recompute
  7. 2026-08-27 22:58 UTCVendor advisory
  8. 2026-08-27 22:58 UTCGHSA enrichment
  9. 2026-08-27 14:25 UTCEPSS rescore
  10. 2026-08-27 11:54 UTCVendor advisory
  11. 2026-08-27 11:54 UTCGHSA enrichment
  12. 2026-08-26 23:00 UTCEG score recompute
  13. 2026-08-26 23:00 UTCGHSA enrichment
  14. 2026-08-26 14:46 UTCEPSS rescore
  15. 2026-08-26 11:55 UTCVendor advisory
  16. 2026-08-26 11:55 UTCGHSA enrichment
  17. 2026-08-26 00:52 UTCEG score recompute
  18. 2026-08-26 00:52 UTCVendor advisory
  19. 2026-08-26 00:52 UTCGHSA enrichment
  20. 2026-08-25 13:49 UTCEPSS rescore
  21. 2026-08-25 12:58 UTCVendor advisory
  22. 2026-08-25 12:58 UTCGHSA enrichment
  23. 2026-08-25 01:53 UTCVendor advisory
  24. 2026-08-25 01:53 UTCGHSA enrichment
  25. 2026-08-24 14:48 UTCEG score recompute
Show 75 more
  1. 2026-08-24 14:48 UTCVendor advisory
  2. 2026-08-24 14:48 UTCGHSA enrichment
  3. 2026-08-24 03:44 UTCVendor advisory
  4. 2026-08-24 03:44 UTCGHSA enrichment
  5. 2026-08-23 15:41 UTCVendor advisory
  6. 2026-08-23 15:41 UTCGHSA enrichment
  7. 2026-08-23 04:38 UTCEG score recompute
  8. 2026-08-23 04:38 UTCVendor advisory
  9. 2026-08-23 04:38 UTCGHSA enrichment
  10. 2026-08-23 00:19 UTCEPSS rescore
  11. 2026-08-22 17:34 UTCVendor advisory
  12. 2026-08-22 17:34 UTCGHSA enrichment
  13. 2026-08-22 06:30 UTCEG score recompute
  14. 2026-08-22 06:30 UTCVendor advisory
  15. 2026-08-22 06:30 UTCGHSA enrichment
  16. 2026-08-21 23:49 UTCEPSS rescore
  17. 2026-08-21 19:26 UTCVendor advisory
  18. 2026-08-21 19:26 UTCGHSA enrichment
  19. 2026-08-21 08:21 UTCEG score recompute
  20. 2026-08-21 08:21 UTCVendor advisory
  21. 2026-08-21 08:21 UTCGHSA enrichment
  22. 2026-08-20 22:55 UTCEPSS rescore
  23. 2026-08-20 21:17 UTCVendor advisory
  24. 2026-08-20 21:17 UTCGHSA enrichment
  25. 2026-08-20 10:13 UTCVendor advisory
  26. 2026-08-20 10:13 UTCGHSA enrichment
  27. 2026-08-19 23:10 UTCEG score recompute
  28. 2026-08-19 23:10 UTCVendor advisory
  29. 2026-08-19 23:10 UTCGHSA enrichment
  30. 2026-08-19 17:04 UTCEPSS rescore
  31. 2026-08-19 06:53 UTCVendor advisory
  32. 2026-08-19 06:53 UTCGHSA enrichment
  33. 2026-08-18 19:50 UTCEG score recompute
  34. 2026-08-18 19:50 UTCVendor advisory
  35. 2026-08-18 19:50 UTCGHSA enrichment
  36. 2026-08-18 13:48 UTCEPSS rescore
  37. 2026-08-18 01:52 UTCEG score recompute
  38. 2026-08-18 01:52 UTCVendor advisory
  39. 2026-08-18 01:52 UTCGHSA enrichment
  40. 2026-08-17 13:47 UTCEPSS rescore
  41. 2026-08-17 13:18 UTCVendor advisory
  42. 2026-08-17 13:18 UTCGHSA enrichment
  43. 2026-08-17 02:15 UTCVendor advisory
  44. 2026-08-17 02:15 UTCGHSA enrichment
  45. 2026-08-16 15:12 UTCEG score recompute
  46. 2026-08-16 15:12 UTCVendor advisory
  47. 2026-08-16 15:12 UTCGHSA enrichment
  48. 2026-08-16 14:56 UTCEPSS rescore
  49. 2026-08-16 04:08 UTCEG score recompute
  50. 2026-08-16 04:08 UTCVendor advisory
  51. 2026-08-16 04:08 UTCGHSA enrichment
  52. 2026-08-15 17:05 UTCVendor advisory
  53. 2026-08-15 17:05 UTCGHSA enrichment
  54. 2026-08-15 06:01 UTCEG score recompute
  55. 2026-08-15 06:01 UTCVendor advisory
  56. 2026-08-15 06:01 UTCGHSA enrichment
  57. 2026-08-15 01:30 UTCEPSS rescore
  58. 2026-08-14 18:57 UTCVendor advisory
  59. 2026-08-14 18:57 UTCGHSA enrichment
  60. 2026-08-14 07:52 UTCEG score recompute
  61. 2026-08-14 07:52 UTCVendor advisory
  62. 2026-08-14 07:52 UTCGHSA enrichment
  63. 2026-08-13 22:00 UTCEPSS rescore
  64. 2026-08-13 20:48 UTCVendor advisory
  65. 2026-08-13 20:48 UTCGHSA enrichment
  66. 2026-08-13 09:44 UTCVendor advisory
  67. 2026-08-13 09:44 UTCGHSA enrichment
  68. 2026-08-12 22:41 UTCEG score recompute
  69. 2026-08-12 22:41 UTCVendor advisory
  70. 2026-08-12 22:41 UTCGHSA enrichment
  71. 2026-08-12 13:51 UTCEPSS rescore
  72. 2026-08-12 11:38 UTCVendor advisory
  73. 2026-08-12 11:38 UTCGHSA enrichment
  74. 2026-08-12 00:34 UTCEG score recompute
  75. 2026-08-12 00:34 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-63923?
CVE-2026-63923 is a high vulnerability published on July 19, 2026. In the Linux kernel, the following vulnerability has been resolved: octeontx2-af: validate body pcifunc in rvumboxhandlerrepevent_notify rvumboxhandlerrepevent_notify() in drivers/net/ethernet/marvell/ octeontx2/af/rvurep.c queues a sender-controlled REPEVENT_NOTIFY request body verbatim, and…
When was CVE-2026-63923 disclosed?
CVE-2026-63923 was first published in the National Vulnerability Database on July 19, 2026, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63923 actively exploited?
CVE-2026-63923 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 93.9% of all scored CVEs.
What is the CVSS score of CVE-2026-63923?
CVE-2026-63923 has a CVSS v4.0 base score of 8.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-63923?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63923, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-63923

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