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NVD / CVE Program· CNA Linux

CVE-2025-21966: dm-flakey: Fix memory corruption in optional corrupt_bio_byte feature

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: 0.21% (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 57e9417f69839cb10f7ffca684c38acd28ceb57b, 5a87e46da2418c57b445371f5ca0958d5779ba5f, 818330f756f3800c37d738bd36bce60eac949938; azl3 kernel 6.6.82.1-1 on Azure Linux 3.0 6.6.85.1-2; azl3 kernel 6.6.85.1-2 on Azure Linux 3.0 6.6.85.1-2.

Low priority for now. Upgrade to Linux Linux 57e9417f69839cb10f7ffca684c38acd28ceb57b, 5a87e46da2418c57b445371f5ca0958d5779ba5f, 818330f756f3800c37d738bd36bce60eac949938; azl3 kernel 6.6.82.1-1 on Azure Linux 3.0 6.6.85.1-2; azl3 kernel 6.6.85.1-2 on Azure Linux 3.0 6.6.85.1-2 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: dm-flakey: Fix memory corruption in optional corrupt_bio_byte feature Fix memory corruption due to incorrect parameter being passed to bio_init

Published
Apr 1, 2025
Updated
Aug 5, 2026
EPSS
0.2% · 11th 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 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
7.8
CNA · Linux
7.8
agree

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-2025-21966

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
    • 1d9a943898533e83f20370c0e1448d606627522e and later · before 818330f756f3800c37d738bd36bce60eac949938affected · git
    • 1d9a943898533e83f20370c0e1448d606627522e and later · before 5a87e46da2418c57b445371f5ca0958d5779ba5faffected · git
    • 1d9a943898533e83f20370c0e1448d606627522e and later · before da070843e153471be4297a12fdaa64023276f40eaffected · git
    • 1d9a943898533e83f20370c0e1448d606627522e and later · before 57e9417f69839cb10f7ffca684c38acd28ceb57baffected · git
    • before 6.5not 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
    • 6.13.8 and later · up to and including 6.13.*not affected · semver
    • 6.14 and laternot affected · original_commit_for_fix
Affected versions · NVD (4)

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

  • linux linux kernel6.5 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
AlmaLinux:9kernelbefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-64kbefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-64k-corebefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-64k-debugbefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-64k-debug-corebefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-64k-debug-develbefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-64k-debug-devel-matchedbefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-64k-debug-modulesbefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-64k-debug-modules-corebefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-64k-debug-modules-extrabefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-64k-develbefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-64k-devel-matchedbefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-64k-modulesbefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-64k-modules-corebefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-64k-modules-extrabefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-abi-stablelistsbefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-corebefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-cross-headersbefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-debugbefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-debug-corebefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-debug-develbefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-debug-devel-matchedbefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-debug-modulesbefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6
AlmaLinux:9kernel-debug-modules-corebefore 5.14.0-570.17.1.el9_65.14.0-570.17.1.el9_6

+96

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-2025-21964Apr 1, 2025 · cifs: Fix integer overflow while processing acregmax mount option
    22Monitor
  • ← EarlierCVE-2025-21965Apr 1, 2025 · sched_ext: Validate prev_cpu in scx_bpf_select_cpu_dfl()
    22Monitor
  • Later →CVE-2025-21968Apr 1, 2025 · drm/amd/display: Fix slab-use-after-free on hdcp_work
    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 Linux57e9417f69839cb10f7ffca684c38acd28ceb57bVendor (CNA)
Linux Linux5a87e46da2418c57b445371f5ca0958d5779ba5fVendor (CNA)
Linux Linux818330f756f3800c37d738bd36bce60eac949938Vendor (CNA)
Linux Linuxda070843e153471be4297a12fdaa64023276f40eVendor (CNA)
azl3 kernel 6.6.82.1-1 on Azure Linux 3.06.6.85.1-2 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.85.1-2 on Azure Linux 3.06.6.85.1-2 · CBL-Mariner ReleasesMicrosoft (MSRC)
almalinux:kernel5.14.0-570.17.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k5.14.0-570.17.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-core5.14.0-570.17.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug5.14.0-570.17.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-core5.14.0-570.17.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel5.14.0-570.17.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched5.14.0-570.17.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules5.14.0-570.17.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-core5.14.0-570.17.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra5.14.0-570.17.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel5.14.0-570.17.1.el9_6 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel-matched5.14.0-570.17.1.el9_6 · AlmaLinux:9Package registry (OSV)
debian:linux6.12.20-1 · Debian:13Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:5.14.0-570.17.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel0:5.14.0-570.17.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel-matched0:5.14.0-570.17.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debuginfo0:5.14.0-570.17.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-devel0:5.14.0-570.17.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-devel-matched0:5.14.0-570.17.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-debuginfo0:5.14.0-570.17.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-devel0:5.14.0-570.17.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-devel-matched0:5.14.0-570.17.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debuginfo0:5.14.0-570.17.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debuginfo-common-aarch640:5.14.0-570.17.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)

+2

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
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

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 (3 more)

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

All records