CVE-2026-64366

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 2026-07-25. 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
Trending — 4 sources updated this week

Also known asEUVD-2026-48910 (ENISA EUVD) · GHSA-4hx3-px5f-mcx4 (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: 0.4%CVSS: 8.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

HID: wacom: fix slab-out-of-bounds write in wacom_wac_queue_insert

wacom_wac_queue_insert() calls kfifo_skip() in a loop when the kfifo doesn't have enough space for the incoming report. If the kfifo is empty, kfifo_skip() reads stale data left in the kmalloc'd buffer via __kfifo_peek_n() and interprets it as a record length, advancing fifo->out by that garbage value. This corrupts the internal kfifo state, causing kfifo_unused() to return a value much larger than the actual buffer size, which bypasses __kfifo_in_r()'s guard:

if (len + recsize > kfifo_unused(fifo)) return 0;

kfifo_copy_in() then performs an out-of-bounds memcpy, writing up to 3842 bytes past the 256-byte buffer.

Add a !kfifo_is_empty() condition to the while loop so kfifo_skip() is never called on an empty fifo, and check the return value of kfifo_in() to reject reports that are too large for the fifo.

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.
Exploitation0.4% × 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
0.4%
EPSS %ILE
34th
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
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-27). 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 25, 2026

Last Modified

October 19, 2026

Advisory Details (3)

Auto-updated Jul 27, 2026
Patch available.
Web page

HID: wacom: fix slab-out-of-bounds write in wacom_wac_queue_insert - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ca899a926c11a59211b764b0155d9a1cdcc32b81
Web page

HID: wacom: fix slab-out-of-bounds write in wacom_wac_queue_insert - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/6b3014ec0e9a390ca563030b2d7689921f0daef5
Web page

HID: wacom: fix slab-out-of-bounds write in wacom_wac_queue_insert - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/57bdd10ad50d68341f500a7b330f0d8949e510ec

Vendor Advisories for CVE-2026-64366(1)

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

Patch Availability(11)

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 ... 7.1~rc7-1~exp1 (159 versions)
  • every version up to 7.1.4-1: fixed in 7.1.4-1
—

Weakness Classification(1)

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

All Vendor Advisories

(11)

Data Freshness Timeline

(refreshed 10× in last 7d / 59× 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 it from the CNA feed. 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). Most recent first.

Showing the most recent 100 of 297 refreshes 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 197 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  4. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  5. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  6. 2026-10-27 18:32 UTCEG score recompute
  7. 2026-10-27 18:32 UTCVendor advisory
  8. 2026-10-27 18:32 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  9. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  10. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  11. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  12. 2026-10-25 14:12 UTCEG score recompute
  13. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  14. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  15. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  16. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  17. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  18. 2026-10-19 21:40 UTCEG score recompute
  19. 2026-10-19 21:40 UTCVendor advisory
  20. 2026-10-19 21:40 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  21. 2026-10-19 20:45 UTCEG score recompute
  22. 2026-10-19 20:45 UTCVendor advisory
  23. 2026-10-19 20:44 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  24. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  25. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.3% · 15th percentile
Show 75 more
  1. 2026-10-18 03:22 UTCEG score recompute
  2. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  3. 2026-10-16 17:14 UTCEG score recompute
  4. 2026-10-16 17:14 UTCVendor advisory
  5. 2026-10-16 17:14 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  6. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  7. 2026-10-16 15:51 UTCEG score recompute
  8. 2026-10-16 15:51 UTCVendor advisory
  9. 2026-10-16 15:51 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  10. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  11. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  12. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  13. 2026-10-13 11:41 UTCEG score recompute
  14. 2026-10-13 11:41 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  15. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  16. 2026-10-12 15:48 UTCEG score recompute
  17. 2026-10-11 19:32 UTCEG score recompute
  18. 2026-10-11 16:47 UTCEG score recompute
  19. 2026-10-11 14:09 UTCEG score recompute
  20. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  21. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  22. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  23. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  24. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  25. 2026-10-07 04:39 UTCEG score recompute
  26. 2026-10-07 04:39 UTCVendor advisory
  27. 2026-10-07 04:39 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  28. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  29. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  30. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  31. 2026-10-04 07:33 UTCEG score recompute
  32. 2026-10-04 07:33 UTCVendor advisory
  33. 2026-10-04 07:33 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  34. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  35. 2026-10-02 19:25 UTCEG score recompute
  36. 2026-10-02 19:25 UTCVendor advisory
  37. 2026-10-02 19:25 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  38. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  39. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  40. 2026-10-01 04:15 UTCEG score recompute
  41. 2026-10-01 04:15 UTCVendor advisory
  42. 2026-10-01 04:15 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  43. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  44. 2026-09-29 08:32 UTCEG score recompute
  45. 2026-09-29 08:32 UTCVendor advisory
  46. 2026-09-29 08:31 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  47. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  48. 2026-09-28 04:15 UTCEG score recompute
  49. 2026-09-28 04:15 UTCVendor advisory
  50. 2026-09-28 04:14 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  51. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  52. 2026-09-25 09:46 UTCEG score recompute
  53. 2026-09-25 09:46 UTCVendor advisory
  54. 2026-09-25 09:46 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  55. 2026-09-24 00:35 UTCEG score recompute
  56. 2026-09-24 00:35 UTCVendor advisory
  57. 2026-09-24 00:35 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  58. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  59. 2026-09-23 11:08 UTCVendor advisory
  60. 2026-09-23 11:08 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  61. 2026-09-22 22:03 UTCEG score recompute
  62. 2026-09-22 22:03 UTCVendor advisory
  63. 2026-09-22 22:03 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  64. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  65. 2026-09-20 01:26 UTCEG score recompute
  66. 2026-09-20 01:26 UTCVendor advisory
  67. 2026-09-20 01:26 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  68. 2026-09-18 19:50 UTCEG score recompute
  69. 2026-09-18 19:50 UTCVendor advisory
  70. 2026-09-18 19:50 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  71. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  72. 2026-09-18 02:48 UTCEG score recompute
  73. 2026-09-18 02:48 UTCVendor advisory
  74. 2026-09-18 02:48 UTCGHSA enrichmentGHSA-4hx3-px5f-mcx4 · GitHub severity HIGH · GitHub CVSS 8.8
  75. 2026-09-17 01:55 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-64366?
CVE-2026-64366 is a high-severity vulnerability; its CVE record was published on July 25, 2026. In the Linux kernel, the following vulnerability has been resolved: HID: wacom: fix slab-out-of-bounds write in wacom_wac_queue_insert wacom_wac_queue_insert() calls kfifo_skip() in a loop when the kfifo doesn't have enough space for the incoming report. If the kfifo is empty, kfifo_skip() reads…
When was the CVE record for CVE-2026-64366 published?
The CVE record for CVE-2026-64366 was published on July 25, 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 19, 2026; the record at its source may have been updated since.
Is CVE-2026-64366 actively exploited?
CVE-2026-64366 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (34th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-64366?
CVE-2026-64366 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-2026-64366?
A fix for CVE-2026-64366 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-64366 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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