CVE-2026-63923

HIGHPre-NVD 8.88.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-19. A secondary CVSS source baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source

Also known asEUVD-2026-45696 (ENISA EUVD) · GHSA-95j3-7q26-w637 (GitHub Security Advisories)Source: ENISA EUVD

8.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 8.8Exploit: None knownExposed services: Not assessed

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
8.8HIGHmedium confidence
EG Risk
40
EG Risk 40/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity88% × 45%
Impact severity (EG Severity): CVSS 8.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
6th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (8.8): severity, escalated by confirmed exploitation. This CVE's 8.8 is its impact severity (EG Severity), not escalated.

EG Severity
8.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-10). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

July 19, 2026

Last Modified

October 27, 2026

Advisory Details (2)

Auto-updated Jul 20, 2026
Patch available.
Web page

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
Web page

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

Patch Availability(10)

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 rangeFix by version rangeDependents
linux6.12.100-1 ... 7.0.9-1~bpo13+1 (143 versions)
  • every version up to 7.0.12-1: fixed in 7.0.12-1
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(8)

Data Freshness Timeline

(refreshed 9× in last 7d / 43× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 360 rows on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 260 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:53 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  2. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  3. 2026-11-11 16:40 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  4. 2026-11-10 20:03 UTCEchelonGraph re-scored
  5. 2026-11-10 20:03 UTCVendor advisory
  6. 2026-11-10 20:03 UTCGHSA enrichmentGHSA-95j3-7q26-w637 · GitHub severity HIGH · GitHub CVSS 8.8
  7. 2026-11-10 16:45 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  8. 2026-11-09 16:35 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  9. 2026-11-08 16:40 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  10. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  11. 2026-11-06 16:39 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  12. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  13. 2026-11-04 16:36 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  14. 2026-11-03 17:04 UTCEchelonGraph re-scored
  15. 2026-11-03 17:04 UTCVendor advisory
  16. 2026-11-03 17:04 UTCGHSA enrichmentGHSA-95j3-7q26-w637 · GitHub severity HIGH · GitHub CVSS 8.8
  17. 2026-11-03 16:48 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  18. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  19. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  20. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  21. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  22. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  23. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  24. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  25. 2026-10-27 13:07 UTCEchelonGraph re-scored
Show 75 more
  1. 2026-10-27 13:07 UTCVendor advisory
  2. 2026-10-27 13:06 UTCGHSA enrichmentGHSA-95j3-7q26-w637 · GitHub severity HIGH · GitHub CVSS 8.8
  3. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  4. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  5. 2026-10-25 14:13 UTCEchelonGraph re-scored
  6. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  7. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  8. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  9. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  10. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  11. 2026-10-19 21:38 UTCEchelonGraph re-scored
  12. 2026-10-19 21:38 UTCVendor advisory
  13. 2026-10-19 21:38 UTCGHSA enrichmentGHSA-95j3-7q26-w637 · GitHub severity HIGH · GitHub CVSS 8.8
  14. 2026-10-19 20:37 UTCEchelonGraph re-scored
  15. 2026-10-19 20:37 UTCVendor advisory
  16. 2026-10-19 20:36 UTCGHSA enrichmentGHSA-95j3-7q26-w637 · GitHub severity HIGH · GitHub CVSS 8.8
  17. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  18. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  19. 2026-10-18 03:23 UTCEchelonGraph re-scored
  20. 2026-10-16 17:19 UTCEchelonGraph re-scored
  21. 2026-10-16 17:19 UTCVendor advisory
  22. 2026-10-16 17:18 UTCGHSA enrichmentGHSA-95j3-7q26-w637 · GitHub severity HIGH · GitHub CVSS 8.8
  23. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  24. 2026-10-16 15:54 UTCEchelonGraph re-scored
  25. 2026-10-16 15:54 UTCVendor advisory
  26. 2026-10-16 15:54 UTCGHSA enrichmentGHSA-95j3-7q26-w637 · GitHub severity HIGH · GitHub CVSS 8.8
  27. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  28. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  29. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  30. 2026-10-13 11:50 UTCEchelonGraph re-scored
  31. 2026-10-13 11:50 UTCVendor advisory
  32. 2026-10-13 11:49 UTCGHSA enrichmentGHSA-95j3-7q26-w637 · GitHub severity HIGH · GitHub CVSS 8.8
  33. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  34. 2026-10-12 15:48 UTCEchelonGraph re-scored
  35. 2026-10-11 19:33 UTCEchelonGraph re-scored
  36. 2026-10-11 16:48 UTCEchelonGraph re-scored
  37. 2026-10-11 14:09 UTCEchelonGraph re-scored
  38. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  39. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  40. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  41. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  42. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  43. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  44. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  45. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  46. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  47. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  48. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  49. 2026-10-01 08:54 UTCEchelonGraph re-scored
  50. 2026-10-01 08:54 UTCVendor advisory
  51. 2026-10-01 08:54 UTCGHSA enrichmentGHSA-95j3-7q26-w637 · GitHub severity HIGH · GitHub CVSS 8.8
  52. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  53. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  54. 2026-09-28 07:29 UTCEchelonGraph re-scored
  55. 2026-09-28 07:29 UTCVendor advisory
  56. 2026-09-28 07:29 UTCGHSA enrichmentGHSA-95j3-7q26-w637 · GitHub severity HIGH · GitHub CVSS 8.8
  57. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  58. 2026-09-24 04:13 UTCEchelonGraph re-scored
  59. 2026-09-24 04:13 UTCVendor advisory
  60. 2026-09-24 04:13 UTCGHSA enrichmentGHSA-95j3-7q26-w637 · GitHub severity HIGH · GitHub CVSS 8.8
  61. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  62. 2026-09-23 02:09 UTCEchelonGraph re-scored
  63. 2026-09-23 02:09 UTCVendor advisory
  64. 2026-09-23 02:09 UTCGHSA enrichmentGHSA-95j3-7q26-w637 · GitHub severity HIGH · GitHub CVSS 8.8
  65. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  66. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  67. 2026-09-18 04:22 UTCEchelonGraph re-scored
  68. 2026-09-18 04:22 UTCVendor advisory
  69. 2026-09-18 04:22 UTCGHSA enrichmentGHSA-95j3-7q26-w637 · GitHub severity HIGH · GitHub CVSS 8.8
  70. 2026-09-17 05:38 UTCEchelonGraph re-scored
  71. 2026-09-17 05:38 UTCVendor advisory
  72. 2026-09-17 05:37 UTCGHSA enrichmentGHSA-95j3-7q26-w637 · GitHub severity HIGH · GitHub CVSS 8.8
  73. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  74. 2026-09-16 13:07 UTCEchelonGraph re-scored
  75. 2026-09-16 13:07 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-63923?
CVE-2026-63923 is a high-severity vulnerability; its CVE record was published on July 19, 2026. 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,…
When was the CVE record for CVE-2026-63923 published?
The CVE record for CVE-2026-63923 was published on July 19, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 27, 2026; the record at its source may have been updated since.
Is CVE-2026-63923 actively exploited?
CVE-2026-63923 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (6th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-63923?
CVE-2026-63923 has a CVSS base score of 8.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-63923?
A fix for CVE-2026-63923 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-63923 are linked in the Vendor Advisories panel on this page.

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