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NVD / CVE Program· CNA Linux

CVE-2025-38639: netfilter: xt_nfacct: don't assume acct name is null-terminated

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: 0.18% (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 58004aa21e79addaf41667bfe65e93ec51653f18, 58007fc7b94fb2702000045ff401eb7f5bde7828, 66d41268ede1e1b6e71ba28be923397ff0b2b9c3; 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 58004aa21e79addaf41667bfe65e93ec51653f18, 58007fc7b94fb2702000045ff401eb7f5bde7828, 66d41268ede1e1b6e71ba28be923397ff0b2b9c3; 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: netfilter: xt_nfacct: don't assume acct name is null-terminated BUG: KASAN: slab-out-of-bounds in .. lib/vsprintf.c:721 Read of size 1 at addr ffff88801eac95c8 by task syz-executor183/5851 [..] string+0x231/0x2b0 lib/vsprintf.c:721 vsnprintf+0x739/0xf00 lib/vsprintf.c:2874 [..] nfacct_mt_checkentry+0xd2/0xe0 net/netfilter/xt_nfacct.c:41 xt_check_match+0x3d1/0xab0 net/netfilter/x_tables.c:523 nfnl_acct_find_get() handles non-null input, but the error printk relied on its presence.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Aug 22, 2025
Updated
Oct 15, 2026
EPSS
0.1% · 8th 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

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2025-38639

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 kernel5.5 and later · before 5.10.241
  • linux linux kernel5.11 and later · before 5.15.190
  • linux linux kernel5.16 and later · before 6.1.148
  • linux linux kernel3.3 and later · before 5.4.297
  • linux linux kernel6.7 and later · before 6.12.42
  • linux linux kernel6.13 and later · before 6.15.10
  • linux linux kernel6.16 and later · before 6.16.1
  • linux linux kernel6.2 and later · before 6.6.102

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

    • 3.3affected
    • ceb98d03eac5704820f2ac1f370c9ff385e3a9f5 and later · before 66d41268ede1e1b6e71ba28be923397ff0b2b9c3affected · git
    • ceb98d03eac5704820f2ac1f370c9ff385e3a9f5 and later · before e021a1eee196887536a6630c5492c23a4c78d452affected · git
    • ceb98d03eac5704820f2ac1f370c9ff385e3a9f5 and later · before b10cfa2de13d28ddd03210eb234422b7ec92725aaffected · git
    • ceb98d03eac5704820f2ac1f370c9ff385e3a9f5 and later · before e18939176e657a3a20bfbed357b8c55a9f82aba3affected · git
    • ceb98d03eac5704820f2ac1f370c9ff385e3a9f5 and later · before 58004aa21e79addaf41667bfe65e93ec51653f18affected · git
    • ceb98d03eac5704820f2ac1f370c9ff385e3a9f5 and later · before 7c1ae471da69c09242834e956218ea6a42dd405aaffected · git
    • ceb98d03eac5704820f2ac1f370c9ff385e3a9f5 and later · before 58007fc7b94fb2702000045ff401eb7f5bde7828affected · git
    • ceb98d03eac5704820f2ac1f370c9ff385e3a9f5 and later · before df13c9c6ce1d55c31d1bd49db65a7fbbd86aab13affected · git
    • ceb98d03eac5704820f2ac1f370c9ff385e3a9f5 and later · before bf58e667af7d96c8eb9411f926a0a0955f41ce21affected · git

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.148-16.1.148-1
Debian:13linuxbefore 6.12.43-16.12.43-1
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-2025-38632Aug 22, 2025 · pinmux: fix race causing mux_owner NULL with active mux_usecount
    18Monitor
  • ← EarlierCVE-2025-38636Aug 22, 2025 · rv: Use strings in da monitors tracepoints
    28Monitor
  • Later →CVE-2025-38640Aug 22, 2025 · bpf: Disable migration in nf_hook_run_bpf().
    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 Linux58004aa21e79addaf41667bfe65e93ec51653f18Vendor (CNA)
Linux Linux58007fc7b94fb2702000045ff401eb7f5bde7828Vendor (CNA)
Linux Linux66d41268ede1e1b6e71ba28be923397ff0b2b9c3Vendor (CNA)
Linux Linux7c1ae471da69c09242834e956218ea6a42dd405aVendor (CNA)
Linux Linuxb10cfa2de13d28ddd03210eb234422b7ec92725aVendor (CNA)
Linux Linuxbf58e667af7d96c8eb9411f926a0a0955f41ce21Vendor (CNA)
Linux Linuxdf13c9c6ce1d55c31d1bd49db65a7fbbd86aab13Vendor (CNA)
Linux Linuxe021a1eee196887536a6630c5492c23a4c78d452Vendor (CNA)
Linux Linuxe18939176e657a3a20bfbed357b8c55a9f82aba3Vendor (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:linux6.1.148-1 · 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