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NVD / CVE Program· CNA Linux

CVE-2025-21853: bpf: avoid holding freeze_mutex during mmap operation

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: 0.24% (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 0d90d9e154144a3a80e9fc0eb9b21b7fc990f68f, 271e49f8a58edba65bc2b1250a0abaa98c4bfdbe, 29cfda62ab4d92ab94123813db49ab76c1e61b29; azl3 kernel 6.6.78.1-3 on Azure Linux 3.0 6.6.82.1-1; azl3 kernel 6.6.82.1-1 on Azure Linux 3.0 6.6.82.1-1.

Low priority for now. Upgrade to Linux Linux 0d90d9e154144a3a80e9fc0eb9b21b7fc990f68f, 271e49f8a58edba65bc2b1250a0abaa98c4bfdbe, 29cfda62ab4d92ab94123813db49ab76c1e61b29; azl3 kernel 6.6.78.1-3 on Azure Linux 3.0 6.6.82.1-1; azl3 kernel 6.6.82.1-1 on Azure Linux 3.0 6.6.82.1-1 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: bpf: avoid holding freeze_mutex during mmap operation We use map->freeze_mutex to prevent races between map_freeze() and memory mapping BPF map contents with writable permissions. The way we naively do this means we'll hold freeze_mutex for entire duration of all the mm and VMA manipulations, which is completely unnecessary. This can potentially also lead to deadlocks, as reported by syzbot in [0]. So, instead, hold freeze_mutex only during writeability checks, bump (proactively) "write active" count for the map, unlock the mutex and proceed with mmap logic. And only if something went wrong during mmap logic, then undo that "write active" counter increment. [0] https://lore.kernel.org/bpf/678dcbc9.050a0220.303755.0066.GAE@google.com/

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Mar 12, 2025
Updated
Nov 5, 2026
EPSS
0.2% · 16th percentile
CWE
—

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-2025-21853

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

Affected versions

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

  • linux linux kernel5.5 and later · before 6.6.80
  • linux linux kernel6.7 and later · before 6.12.17
  • linux linux kernel6.13 and later · before 6.13.5
  • linux linux kernel6.14

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

    • 5.5affected
    • fc9702273e2edb90400a34b3be76f7b08fa3344b and later · before 2ce31c97c219b4fe797749f950274f246eb88c49affected · git
    • fc9702273e2edb90400a34b3be76f7b08fa3344b and later · before 0d90d9e154144a3a80e9fc0eb9b21b7fc990f68faffected · git
    • fc9702273e2edb90400a34b3be76f7b08fa3344b and later · before 4759acbd44d24a69b7b14848012ec4201d6c5501affected · git
    • fc9702273e2edb90400a34b3be76f7b08fa3344b and later · before 29cfda62ab4d92ab94123813db49ab76c1e61b29affected · git
    • fc9702273e2edb90400a34b3be76f7b08fa3344b and later · before d95607a5f2f9bb08194c9deaf4a5f3e8ba59a9d4affected · git
    • fc9702273e2edb90400a34b3be76f7b08fa3344b and later · before 271e49f8a58edba65bc2b1250a0abaa98c4bfdbeaffected · git
    • fc9702273e2edb90400a34b3be76f7b08fa3344b and later · before bc27c52eea189e8f7492d40739b7746d67b65bebaffected · git
    • before 5.5not affected · semver
    • 5.10.237 and later · up to and including 5.10.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.135-16.1.135-1
Debian:13linuxbefore 6.12.17-16.12.17-1

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-2025-21844Mar 12, 2025 · smb: client: Add check for next_buffer in receive_encrypted_standard()
    22Monitor
  • ← EarlierCVE-2025-21846Mar 12, 2025 · acct: perform last write from workqueue
    22Monitor
  • Later →CVE-2025-21858Mar 12, 2025 · geneve: Fix use-after-free in geneve_find_dev().
    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 Linux0d90d9e154144a3a80e9fc0eb9b21b7fc990f68fVendor (CNA)
Linux Linux271e49f8a58edba65bc2b1250a0abaa98c4bfdbeVendor (CNA)
Linux Linux29cfda62ab4d92ab94123813db49ab76c1e61b29Vendor (CNA)
Linux Linux2ce31c97c219b4fe797749f950274f246eb88c49Vendor (CNA)
Linux Linux4759acbd44d24a69b7b14848012ec4201d6c5501Vendor (CNA)
Linux Linuxbc27c52eea189e8f7492d40739b7746d67b65bebVendor (CNA)
Linux Linuxd95607a5f2f9bb08194c9deaf4a5f3e8ba59a9d4Vendor (CNA)
azl3 kernel 6.6.78.1-3 on Azure Linux 3.06.6.82.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.82.1-1 on Azure Linux 3.06.6.82.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.182.1-1 on CBL Mariner 2.0CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.182.1-1 on CBL-Mariner 2.05.15.182.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.135-1 · 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.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

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

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

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)

—

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.

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (10 more)

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

All records