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NVD / CVE Program· CNA Linux

CVE-2025-38528: bpf: Reject %p% format string in bprintf-like helpers

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: 0.17% (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 1c5f5fd47bbda17cb885fe6f03730702cd53d3f8, 61d5fa45ed13e42af14c7e959baba9908b8ee6d4, 6952aeace93f8c9ea01849efecac24dd3152c9c9; azl3 kernel 6.6.96.2-2 on Azure Linux 3.0 6.6.104.2-1; cbl2 kernel 5.15.186.1-1 on CBL Mariner 2.0 5.15.200.1-1.

Low priority for now. Upgrade to Linux Linux 1c5f5fd47bbda17cb885fe6f03730702cd53d3f8, 61d5fa45ed13e42af14c7e959baba9908b8ee6d4, 6952aeace93f8c9ea01849efecac24dd3152c9c9; azl3 kernel 6.6.96.2-2 on Azure Linux 3.0 6.6.104.2-1; cbl2 kernel 5.15.186.1-1 on CBL Mariner 2.0 5.15.200.1-1 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: Reject %p% format string in bprintf-like helpers static const char fmt[] = "%p%"; bpf_trace_printk(fmt, sizeof(fmt)); The above BPF program isn't rejected and causes a kernel warning at runtime: Please remove unsupported %\x00 in format string WARNING: CPU: 1 PID: 7244 at lib/vsprintf.c:2680 format_decode+0x49c/0x5d0 This happens because bpf_bprintf_prepare skips over the second %, detected as punctuation, while processing %p. This patch fixes it by not skipping over punctuation. %\x00 is then processed in the next iteration and rejected.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Aug 16, 2025
Updated
Oct 15, 2026
EPSS
0.1% · 6th 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 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
5.5
CNA · Linux
7.1
1.6 point gap

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

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

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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
debiandebian linux

Affected versions

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

  • debian debian linux11.0
  • linux linux kernel5.16 and later · before 6.1.147
  • linux linux kernel6.2 and later · before 6.6.100
  • linux linux kernel5.13 and later · before 5.15.190
  • linux linux kernel6.13 and later · before 6.15.8
  • linux linux kernel6.7 and later · before 6.12.40
  • linux linux kernel6.16

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

    • 5.13affected
    • 48cac3f4a96ddf08df8e53809ed066de0dc93915 and later · before 97303e541e12f1fea97834ec64b98991e8775f39affected · git
    • 48cac3f4a96ddf08df8e53809ed066de0dc93915 and later · before 61d5fa45ed13e42af14c7e959baba9908b8ee6d4affected · git
    • 48cac3f4a96ddf08df8e53809ed066de0dc93915 and later · before e7be679124bae8cf4fa6e40d7e1661baddfb3289affected · git
    • 48cac3f4a96ddf08df8e53809ed066de0dc93915 and later · before 6952aeace93f8c9ea01849efecac24dd3152c9c9affected · git
    • 48cac3f4a96ddf08df8e53809ed066de0dc93915 and later · before 1c5f5fd47bbda17cb885fe6f03730702cd53d3f8affected · git
    • 48cac3f4a96ddf08df8e53809ed066de0dc93915 and later · before f8242745871f81a3ac37f9f51853d12854fd0b58affected · git
    • before 5.13not affected · semver
    • 5.15.190 and later · up to and including 5.15.*not affected · semver
    • 6.1.147 and later · up to and including 6.1.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.147-16.1.147-1
Debian:13linuxbefore 6.12.41-16.12.41-1
Debian:14linuxbefore 6.16.3-16.16.3-1

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-2025-38526Aug 16, 2025 · ice: add NULL check in eswitch lag check
    22Monitor
  • ← EarlierCVE-2025-38527Aug 16, 2025 · smb: client: fix use-after-free in cifs_oplock_break
    31Monitor
  • Later →CVE-2025-38531Aug 16, 2025 · iio: common: st_sensors: Fix use of uninitialize device structs
    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 Linux1c5f5fd47bbda17cb885fe6f03730702cd53d3f8Vendor (CNA)
Linux Linux61d5fa45ed13e42af14c7e959baba9908b8ee6d4Vendor (CNA)
Linux Linux6952aeace93f8c9ea01849efecac24dd3152c9c9Vendor (CNA)
Linux Linux97303e541e12f1fea97834ec64b98991e8775f39Vendor (CNA)
Linux Linuxe7be679124bae8cf4fa6e40d7e1661baddfb3289Vendor (CNA)
Linux Linuxf8242745871f81a3ac37f9f51853d12854fd0b58Vendor (CNA)
azl3 kernel 6.6.96.2-2 on Azure Linux 3.06.6.104.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.186.1-1 on CBL Mariner 2.05.15.200.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.147-1 · 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 (6 more)

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

All records