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NVD / CVE Program· CNA Linux

CVE-2026-63852: drm/amdgpu/vcn: set no_user_fence for VCN v4.0.3 enc ring

HighCVSS 7.8 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.17% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 0177ac6141c8857130cf365369c74dee7b6b1f7f, 387b7c7667bd5c53549350ddad866d2fcf75a529, 4532b52b34e4e4310386e6fdf6a643368599f522.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 0177ac6141c8857130cf365369c74dee7b6b1f7f, 387b7c7667bd5c53549350ddad866d2fcf75a529, 4532b52b34e4e4310386e6fdf6a643368599f522 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/vcn: set no_user_fence for VCN v4.0.3 enc ring VCN encoder and decoder rings do not support 64-bit user fence writes, reject CS submissions with user fences. (cherry picked from commit ff1a5a125c5a70c328806b9bc01d7d942cf3f9aa)

Published
Jul 19, 2026
Updated
Oct 26, 2026
EPSS
0.1% · 7th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-63852

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 6.5affected
    • b889ef4ac98837838c38f7b9f72bba2f33ee367d and later · before c12a5d35033c0640c57c10d7111c010c7b9c2c8eaffected · git
    • b889ef4ac98837838c38f7b9f72bba2f33ee367d and later · before 387b7c7667bd5c53549350ddad866d2fcf75a529affected · git
    • b889ef4ac98837838c38f7b9f72bba2f33ee367d and later · before 9076a83e5adefd10dc5c967c7b8bde601c4c512aaffected · git
    • b889ef4ac98837838c38f7b9f72bba2f33ee367d and later · before 0177ac6141c8857130cf365369c74dee7b6b1f7faffected · git
    • b889ef4ac98837838c38f7b9f72bba2f33ee367d and later · before 4532b52b34e4e4310386e6fdf6a643368599f522affected · git
    • before 6.5not affected · semver
    • 6.6.141 and later · up to and including 6.6.*not affected · semver
    • 6.12.91 and later · up to and including 6.12.*not affected · semver
    • 6.18.33 and later · up to and including 6.18.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:13linuxbefore 6.12.94-16.12.94-1
Debian:14linuxbefore 7.0.10-17.0.10-1

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-63850Jul 19, 2026 · drm/amdgpu/vcn: set no_user_fence for VCN v5.0.0 enc ring
    31Monitor
  • ← EarlierCVE-2026-63851Jul 19, 2026 · drm/amdgpu/vcn: set no_user_fence for VCN v4.0.5 enc ring
    31Monitor
  • Later →CVE-2026-63853Jul 19, 2026 · drm/amdgpu/vcn: set no_user_fence for VCN v4.0 enc ring
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux0177ac6141c8857130cf365369c74dee7b6b1f7fVendor (CNA)
Linux Linux387b7c7667bd5c53549350ddad866d2fcf75a529Vendor (CNA)
Linux Linux4532b52b34e4e4310386e6fdf6a643368599f522Vendor (CNA)
Linux Linux9076a83e5adefd10dc5c967c7b8bde601c4c512aVendor (CNA)
Linux Linuxc12a5d35033c0640c57c10d7111c010c7b9c2c8eVendor (CNA)
debian:linux6.12.94-1 · Debian:13Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-640370 days apartwifi: iwlwifi: mld: fix TSO segmentation explosion when AMSDU is disabled
    39Monitor
  • CVE-2026-640460 days apartnet: tls: prevent chain-after-chain in plain text SG
    39Monitor
  • CVE-2026-5322124 days apartip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()
    39Monitor
  • CVE-2026-4611552 days apartblock: add pgmap check to biovec_phys_mergeable
    39Monitor
  • CVE-2026-4311474 days apartnetfilter: nft_set_pipapo_avx2: don't return non-matching entry on expiry
    37Monitor
  • CVE-2026-641060 days apartKVM: arm64: vgic-its: Reject restored DTE with out-of-range num_eventid_bits
    36Monitor

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Not on record for this CVE: patch commit or PR link · researcher credit · public bounty program.

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

References

All records