CVE-2026-63856

HIGHPre-NVD 7.87.8
EchelonGraph scoreMEDIUM confidence

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

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-19. A secondary CVSS source baseline 7.8; 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
7.8EG
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: 7.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

drm/amdgpu/vcn: set no_user_fence for VCN v2.0 enc/dec rings

VCN encoder and decoder rings do not support 64-bit user fence writes, reject CS submissions with user fences.

(cherry picked from commit e2b5499fca55f1a32960a311bbb62e35891eaf73)

CVSS v3
7.8
EG Score
7.8HIGHmedium confidence
EG Risk
35
EG Risk 35/100

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)
Severity78% × 45%
Impact severity (EG Severity): CVSS 7.8 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 (7.8): severity, escalated by confirmed exploitation. This CVE's 7.8 is its impact severity (EG Severity), not escalated.

EG Severity
7.8 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 2026-10-19). 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: 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.

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 19, 2026

Advisory Details (5)

Auto-updated Jul 21, 2026
Patch available.
Web page

drm/amdgpu/vcn: set no_user_fence for VCN v2.0 enc/dec rings - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f264019be80de79f84f464846451445923bffea0
Web page

drm/amdgpu/vcn: set no_user_fence for VCN v2.0 enc/dec rings - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c71aecae98e42dcf2baf462df50b3a2cf1a93fe4
Web page

drm/amdgpu/vcn: set no_user_fence for VCN v2.0 enc/dec rings - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ac06ce5cac9e711281585d09d00c6efcd9b86396
Web page

drm/amdgpu/vcn: set no_user_fence for VCN v2.0 enc/dec rings - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8d80b293b41fcb5e9396db93e788b0f4ebcbafb7
Web page

drm/amdgpu/vcn: set no_user_fence for VCN v2.0 enc/dec rings - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/5e777bc4cbe928ac0fd95e368fee1540f2ce4db2

Vendor Advisories for CVE-2026-63856(1)

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

Patch Availability(21)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulinux-tools-aws-fips-6.8 (6.8.0-1061.64+fips1) @ noble2026-10-19ubuntu
ubuntulinux-tools-azure-fde-6.8 (6.8.0-1062.69~22.04.1) @ jammy2026-10-19ubuntu
ubuntulinux-tools-oracle-lts-24.04 (6.8.0-1058.61) @ noble2026-10-19ubuntu
ubuntulinux-xilinx-zynqmp (6.8.0.1033.34) @ noble2026-10-19ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1059.62.1) @ noble2026-10-19ubuntu
ubuntulinux-virtual-hwe-22.04-edge (6.8.0-136.136~22.04.1) @ jammy2026-10-19ubuntu
ubuntulinux-tools-azure-edge (7.0.0-1014.14~24.04.1) @ noble2026-10-19ubuntu
ubuntulinux-tools-gcp-fips-6.8 (6.8.0-1064.72+fips1) @ noble2026-10-19ubuntu
ubuntulinux-tools-oracle-edge (6.8.0-1058.61~22.04.1) @ jammy2026-10-19ubuntu
ubuntulinux-tools-azure-fde-7.0 (7.0.0-1009.9) @ resolute2026-10-19ubuntu
ubuntulinux-tools-aws-lts-24.04 (6.8.0-1061.64+1) @ noble2026-10-19ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1063.71) @ noble2026-10-19ubuntu
ubuntulinux-tools-azure-fde-lts-24.04 (6.8.0-1062.69) @ noble2026-10-19ubuntu
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1063.71+fips2) @ noble2026-10-19ubuntu
ubuntulinux-tools-raspi-realtime-7.0 (7.0.0-1015.15) @ resolute2026-10-19ubuntu
ubuntulinux-tools-nvidia-hwe-26.04 (7.0.0-2016.16) @ resolute2026-10-19ubuntu
ubuntulinux-tools-gcp-edge (7.0.0-1011.11~24.04.1) @ noble2026-10-19ubuntu
ubuntulinux-tools-oracle-edge (7.0.0-1011.11~24.04.1) @ noble2026-10-19ubuntu
ubuntulinux-tools-raspi-realtime-6.8 (6.8.0-2050.52) @ noble2026-10-19ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1016.16) @ resolute2026-10-19ubuntu
ubuntulinux-tools-oracle-7.0 (7.0.0-1008.8) @ resolute2026-10-19ubuntu

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

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
linux5.10.103-1 ... 7.2~rc5-1~exp1 (496 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 7.2~rc7-1~exp1 (358 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.38-1 ... 6.12.94-1~bpo12+1 (27 versions)
  • every version up to 6.12.94-1: fixed in 6.12.94-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.0.9-1~bpo13+1 (141 versions)
  • every version up to 7.0.10-1: fixed in 7.0.10-1
—

Weakness Classification(1)

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

All Vendor Advisories

(21)

Data Freshness Timeline

(refreshed 21× in last 7d / 54× 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 298 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 198 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-19 20:47 UTCEG score recompute
  2. 2026-10-19 20:47 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  3. 2026-10-19 20:19 UTCEG score recompute
  4. 2026-10-19 20:19 UTCVendor advisory
  5. 2026-10-19 20:19 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  6. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  7. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  8. 2026-10-18 03:23 UTCEG score recompute
  9. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  10. 2026-10-16 17:20 UTCEG score recompute
  11. 2026-10-16 17:19 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  12. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  13. 2026-10-16 15:56 UTCEG score recompute
  14. 2026-10-16 15:56 UTCVendor advisory
  15. 2026-10-16 15:55 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  16. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  17. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  18. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  19. 2026-10-13 11:50 UTCEG score recompute
  20. 2026-10-13 11:50 UTCVendor advisory
  21. 2026-10-13 11:50 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  22. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  23. 2026-10-12 15:48 UTCEG score recompute
  24. 2026-10-11 19:33 UTCEG score recompute
  25. 2026-10-11 16:48 UTCEG score recompute
Show 75 more
  1. 2026-10-11 14:09 UTCEG score recompute
  2. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  3. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  4. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  5. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  6. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  7. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  8. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  9. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  10. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  11. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  12. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  13. 2026-10-01 09:06 UTCEG score recompute
  14. 2026-10-01 09:06 UTCVendor advisory
  15. 2026-10-01 09:06 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  16. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  17. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  18. 2026-09-28 07:36 UTCEG score recompute
  19. 2026-09-28 07:36 UTCVendor advisory
  20. 2026-09-28 07:36 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  21. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  22. 2026-09-24 04:16 UTCEG score recompute
  23. 2026-09-24 04:16 UTCVendor advisory
  24. 2026-09-24 04:16 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  25. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  26. 2026-09-23 02:12 UTCEG score recompute
  27. 2026-09-23 02:12 UTCVendor advisory
  28. 2026-09-23 02:12 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  29. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  30. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  31. 2026-09-18 04:25 UTCEG score recompute
  32. 2026-09-18 04:25 UTCVendor advisory
  33. 2026-09-18 04:24 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  34. 2026-09-17 10:04 UTCEG score recompute
  35. 2026-09-17 10:04 UTCVendor advisory
  36. 2026-09-17 10:04 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  37. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  38. 2026-09-16 13:09 UTCEG score recompute
  39. 2026-09-16 13:09 UTCVendor advisory
  40. 2026-09-16 13:09 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  41. 2026-09-14 05:22 UTCEG score recompute
  42. 2026-09-14 05:22 UTCVendor advisory
  43. 2026-09-14 05:22 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  44. 2026-09-13 16:30 UTCVendor advisory
  45. 2026-09-13 16:30 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  46. 2026-09-13 03:38 UTCEG score recompute
  47. 2026-09-13 03:38 UTCVendor advisory
  48. 2026-09-13 03:38 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  49. 2026-09-12 10:21 UTCVendor advisory
  50. 2026-09-12 10:20 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  51. 2026-09-11 19:42 UTCEG score recompute
  52. 2026-09-11 19:42 UTCVendor advisory
  53. 2026-09-11 19:42 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  54. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  55. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  56. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  57. 2026-09-07 23:43 UTCEG score recompute
  58. 2026-09-07 23:43 UTCVendor advisory
  59. 2026-09-07 23:43 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  60. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  61. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  62. 2026-09-06 13:07 UTCVendor advisory
  63. 2026-09-06 13:07 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  64. 2026-09-05 20:13 UTCEG score recompute
  65. 2026-09-05 20:13 UTCVendor advisory
  66. 2026-09-05 20:13 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  67. 2026-09-05 15:31 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  68. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  69. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  70. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  71. 2026-08-31 04:45 UTCEG score recompute
  72. 2026-08-31 04:45 UTCVendor advisory
  73. 2026-08-31 04:44 UTCGHSA enrichmentGHSA-g8wx-jx25-gcm6 · GitHub severity HIGH · GitHub CVSS 7.8
  74. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  75. 2026-08-30 15:52 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-63856?
CVE-2026-63856 is a high-severity vulnerability; its CVE record was published on July 19, 2026. In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/vcn: set nouserfence for VCN v2.0 enc/dec rings VCN encoder and decoder rings do not support 64-bit user fence writes, reject CS submissions with user fences. (cherry picked from commit…
When was the CVE record for CVE-2026-63856 published?
The CVE record for CVE-2026-63856 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 19, 2026; the record at its source may have been updated since.
Is CVE-2026-63856 actively exploited?
CVE-2026-63856 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-2026-63856?
CVE-2026-63856 has a CVSS base score of 7.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-63856?
A fix for CVE-2026-63856 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-63856 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-63856

Explore →

Is Your Infrastructure Affected by CVE-2026-63856?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.