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NVD / CVE Program· CNA Linux

CVE-2025-21728: bpf: Send signals asynchronously if !preemptible

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: 0.21% (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 092fc76b7ab4163e008f9cde596a58dad2108260, 5.4.291, 5.6.

Low priority for now. Upgrade to Linux Linux 092fc76b7ab4163e008f9cde596a58dad2108260, 5.4.291, 5.6 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: Send signals asynchronously if !preemptible BPF programs can execute in all kinds of contexts and when a program running in a non-preemptible context uses the bpf_send_signal() kfunc, it will cause issues because this kfunc can sleep. Change `irqs_disabled()` to `!preemptible()`.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Feb 27, 2025
Updated
Oct 15, 2026
EPSS
0.2% · 11th 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%

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.

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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 kernel5.4.33 and later · before 5.4.291
  • linux linux kernel5.5.18 and later · before 5.6
  • linux linux kernel5.6.1 and later · before 5.10.235
  • linux linux kernel5.11 and later · before 5.15.179
  • linux linux kernel5.16 and later · before 6.1.129
  • linux linux kernel6.2 and later · before 6.6.76
  • linux linux kernel6.7 and later · before 6.12.13
  • linux linux kernel6.13 and later · before 6.13.2
  • linux linux kernel5.6

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

    • 7930d01afb7281edd9782971e0cca6fe587c7a7b, 5.6affected
    • fd29a0242f86b2d95ad666aa9f92a3d0f7bfdab6 and later · before feba1308bc5e8e04cee751d39fae8a9b407a9034affected · git
    • 1bc7896e9ef44fd77858b3ef0b8a6840be3a4494 and later · before ce51eab2070e295d298f42a2f1db269cd1b56d55affected · git
    • 1bc7896e9ef44fd77858b3ef0b8a6840be3a4494 and later · before e306eaaa3d78b462db5f5b11e0171f9d2b6ca3f4affected · git
    • 1bc7896e9ef44fd77858b3ef0b8a6840be3a4494 and later · before be42a09fe898635b0093c0c8dac1bfabe225c240affected · git
    • 1bc7896e9ef44fd77858b3ef0b8a6840be3a4494 and later · before eeef8e65041a031bd8a747a392c14b76a123a12caffected · git
    • 1bc7896e9ef44fd77858b3ef0b8a6840be3a4494 and later · before 78b97783496b454435639937db3303e900a24d3faffected · git
    • 1bc7896e9ef44fd77858b3ef0b8a6840be3a4494 and later · before 092fc76b7ab4163e008f9cde596a58dad2108260affected · git
    • 1bc7896e9ef44fd77858b3ef0b8a6840be3a4494 and later · before 87c544108b612512b254c8f79aa5c0a8546e2cc4affected · git
    • 5.4.33 and later · before 5.4.291affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.129-16.1.129-1
Debian:13linuxbefore 6.12.13-16.12.13-1

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-2025-21726Feb 27, 2025 · padata: avoid UAF for reorder_work
    31Monitor
  • ← EarlierCVE-2025-21727Feb 27, 2025 · padata: fix UAF in padata_reorder
    31Monitor
  • Later →CVE-2025-21729Feb 27, 2025 · wifi: rtw89: fix race between cancel_hw_scan and hw_scan completion
    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 Linux092fc76b7ab4163e008f9cde596a58dad2108260Vendor (CNA)
Linux Linux5.4.291Vendor (CNA)
Linux Linux5.6Vendor (CNA)
Linux Linux78b97783496b454435639937db3303e900a24d3fVendor (CNA)
Linux Linux87c544108b612512b254c8f79aa5c0a8546e2cc4Vendor (CNA)
Linux Linuxbe42a09fe898635b0093c0c8dac1bfabe225c240Vendor (CNA)
Linux Linuxce51eab2070e295d298f42a2f1db269cd1b56d55Vendor (CNA)
Linux Linuxe306eaaa3d78b462db5f5b11e0171f9d2b6ca3f4Vendor (CNA)
Linux Linuxeeef8e65041a031bd8a747a392c14b76a123a12cVendor (CNA)
Linux Linuxfeba1308bc5e8e04cee751d39fae8a9b407a9034Vendor (CNA)
debian:linux6.1.129-1 · 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. Fix✗ → ✓

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

References

Show all references (12 more)

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

All records