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NVD / CVE Program· CNA Linux

CVE-2025-21978: drm/hyperv: Fix address space leak when Hyper-V DRM device is removed

MediumCVSS 5.5 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.20% (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 158242b56bf465a73e1edeac0fe828a8acad4499, 24f1bbfb2be77dad82489c1468bbb14312aab129, ad27b4a51495490b815580d9b935e8eee14d1a9c.

Low priority for now. Upgrade to Linux Linux 158242b56bf465a73e1edeac0fe828a8acad4499, 24f1bbfb2be77dad82489c1468bbb14312aab129, ad27b4a51495490b815580d9b935e8eee14d1a9c 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/hyperv: Fix address space leak when Hyper-V DRM device is removed When a Hyper-V DRM device is probed, the driver allocates MMIO space for the vram, and maps it cacheable. If the device removed, or in the error path for device probing, the MMIO space is released but no unmap is done. Consequently the kernel address space for the mapping is leaked. Fix this by adding iounmap() calls in the device removal path, and in the error path during device probing.

Published
Apr 1, 2025
Updated
Nov 5, 2026
EPSS
0.2% · 9th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

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-2025-21978

When you'll hear from us

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  • 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

    • 6.0affected
    • a0ab5abced550ddeefddb06055ed60779a54eb79 and later · before c40cd24bfb9bfbb315c118ca14ebe6cf52e2dd1eaffected · git
    • a0ab5abced550ddeefddb06055ed60779a54eb79 and later · before ad27b4a51495490b815580d9b935e8eee14d1a9caffected · git
    • a0ab5abced550ddeefddb06055ed60779a54eb79 and later · before 24f1bbfb2be77dad82489c1468bbb14312aab129affected · git
    • a0ab5abced550ddeefddb06055ed60779a54eb79 and later · before 158242b56bf465a73e1edeac0fe828a8acad4499affected · git
    • a0ab5abced550ddeefddb06055ed60779a54eb79 and later · before aed709355fd05ef747e1af24a1d5d78cd7feb81eaffected · git
    • before 6.0not affected · semver
    • 6.1.132 and later · up to and including 6.1.*not affected · semver
    • 6.6.84 and later · up to and including 6.6.*not affected · semver
    • 6.12.20 and later · up to and including 6.12.*not affected · semver
Affected versions · NVD (5)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel6.0 and later · before 6.1.132
  • linux linux kernel6.2 and later · before 6.6.84
  • linux linux kernel6.7 and later · before 6.12.20
  • linux linux kernel6.13 and later · before 6.13.8
  • linux linux kernel6.14

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.133-16.1.133-1
Debian:13linuxbefore 6.12.20-16.12.20-1

Same product

linux: all records

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-2025-21975Apr 1, 2025 · net/mlx5: handle errors in mlx5_chains_create_table()
    22Monitor
  • ← EarlierCVE-2025-21976Apr 1, 2025 · fbdev: hyperv_fb: Allow graceful removal of framebuffer
    22Monitor
  • Later →CVE-2025-21986Apr 1, 2025 · net: switchdev: Convert blocking notification chain to a raw one
    22Monitor

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 Linux158242b56bf465a73e1edeac0fe828a8acad4499Vendor (CNA)
Linux Linux24f1bbfb2be77dad82489c1468bbb14312aab129Vendor (CNA)
Linux Linuxad27b4a51495490b815580d9b935e8eee14d1a9cVendor (CNA)
Linux Linuxaed709355fd05ef747e1af24a1d5d78cd7feb81eVendor (CNA)
Linux Linuxc40cd24bfb9bfbb315c118ca14ebe6cf52e2dd1eVendor (CNA)
debian:linux6.1.133-1 · Debian:12Package 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.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · 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
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-401 · Missing Release of Memory after Effective Lifetime

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records