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NVD / CVE Program· CNA Linux

CVE-2026-31673: af_unix: read UNIX_DIAG_VFS data under unix_state_lock

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: 0.13% (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 0c739f3785f84af695952c2bac8be2f45082c9b8, 39897df386376912d561d4946499379effa1e7ef, 4f6a8f10182c3a9d22e8eb183957ae7ade9e4bf7; azl3 kernel 6.6.134.1-2 on Azure Linux 3.0 6.6.137.1-1.

Low priority for now. Upgrade to Linux Linux 0c739f3785f84af695952c2bac8be2f45082c9b8, 39897df386376912d561d4946499379effa1e7ef, 4f6a8f10182c3a9d22e8eb183957ae7ade9e4bf7; azl3 kernel 6.6.134.1-2 on Azure Linux 3.0 6.6.137.1-1 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: af_unix: read UNIX_DIAG_VFS data under unix_state_lock Exact UNIX diag lookups hold a reference to the socket, but not to u->path. Meanwhile, unix_release_sock() clears u->path under unix_state_lock() and drops the path reference after unlocking. Read the inode and device numbers for UNIX_DIAG_VFS while holding unix_state_lock(), then emit the netlink attribute after dropping the lock. This keeps the VFS data stable while the reply is being built.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Apr 25, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 2th 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 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.8
NVD has not scored this yet; the score shown is the CNA’s.

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-2026-31673

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 kernel3.3 and later · before 6.6.136
  • linux linux kernel6.7 and later · before 6.12.83
  • linux linux kernel6.13 and later · before 6.18.24
  • linux linux kernel6.19 and later · before 6.19.14
  • linux linux kernel7.0

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
    • 5f7b0569460b7d8d01ca776430a00505a68b7584 and later · before e7339db13b9ddb63417b12da55fd6191e59f7442affected · git
    • 5f7b0569460b7d8d01ca776430a00505a68b7584 and later · before 4f6a8f10182c3a9d22e8eb183957ae7ade9e4bf7affected · git
    • 5f7b0569460b7d8d01ca776430a00505a68b7584 and later · before c3ec44ab4526bbc4b6c9fc845af86488244f4c9baffected · git
    • 5f7b0569460b7d8d01ca776430a00505a68b7584 and later · before b9232421a77a649c9376c99fdfc8cb7f79cad34caffected · git
    • 5f7b0569460b7d8d01ca776430a00505a68b7584 and later · before 0c739f3785f84af695952c2bac8be2f45082c9b8affected · git
    • 5f7b0569460b7d8d01ca776430a00505a68b7584 and later · before 900a4e0910e98b8caef117d5df00471fa438dcf9affected · git
    • 5f7b0569460b7d8d01ca776430a00505a68b7584 and later · before bdf206e740bf2919d818f132c8c9cc7ed91d11c0affected · git
    • 5f7b0569460b7d8d01ca776430a00505a68b7584 and later · before 39897df386376912d561d4946499379effa1e7efaffected · git
    • before 3.3not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.176-16.1.176-1
Debian:13linuxbefore 6.12.85-16.12.85-1
Debian:14linuxbefore 6.19.14-16.19.14-1

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-2026-31672Apr 24, 2026 · wifi: rt2x00usb: fix devres lifetime
    22Monitor
  • ← EarlierCVE-2026-31683Apr 25, 2026 · batman-adv: avoid OGM aggregation when skb tailroom is insufficient
    31Monitor
  • Later →CVE-2026-31674Apr 25, 2026 · netfilter: ip6t_rt: reject oversized addrnr in rt_mt6_check()
    28Monitor

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 Linux0c739f3785f84af695952c2bac8be2f45082c9b8Vendor (CNA)
Linux Linux39897df386376912d561d4946499379effa1e7efVendor (CNA)
Linux Linux4f6a8f10182c3a9d22e8eb183957ae7ade9e4bf7Vendor (CNA)
Linux Linux900a4e0910e98b8caef117d5df00471fa438dcf9Vendor (CNA)
Linux Linuxb9232421a77a649c9376c99fdfc8cb7f79cad34cVendor (CNA)
Linux Linuxbdf206e740bf2919d818f132c8c9cc7ed91d11c0Vendor (CNA)
Linux Linuxc3ec44ab4526bbc4b6c9fc845af86488244f4c9bVendor (CNA)
Linux Linuxe7339db13b9ddb63417b12da55fd6191e59f7442Vendor (CNA)
azl3 kernel 6.6.134.1-2 on Azure Linux 3.06.6.137.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.176-1 · 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
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-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

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

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

References

Show all references (8 more)

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

All records