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NVD / CVE Program· CNA Linux

CVE-2025-40158: ipv6: use RCU in ip6_output()

Noroxi assessment

Priority: Monitor (action score 32/100)

  • 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: 0.55% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: Linux Linux 0393f85c3241c19ba8550f04a812e7d19f6b3082, 11709573cc4e48dc34c80fc7ab9ce5b159e29695, 423895685f367b5a0a956bd14b02df0192bded4c; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes.

Low priority for now. Upgrade to Linux Linux 0393f85c3241c19ba8550f04a812e7d19f6b3082, 11709573cc4e48dc34c80fc7ab9ce5b159e29695, 423895685f367b5a0a956bd14b02df0192bded4c; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes 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: ipv6: use RCU in ip6_output() Use RCU in ip6_output() in order to use dst_dev_rcu() to prevent possible UAF. We can remove rcu_read_lock()/rcu_read_unlock() pairs from ip6_finish_output2().

HighCVSS 8.1 · v3.1—No exploit Fix available
Published
Nov 12, 2025
Updated
Oct 30, 2026
EPSS
0.5% · 46th percentile
CWE
—

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
8.1
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.

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  • 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 exploit code appears or is weaponized
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  • 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.

—

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

    • 4.13affected
    • 4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 and later · before 4549ce1057363c8dc072f40c6aa591c279eafed2affected · git
    • 4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 and later · before 423895685f367b5a0a956bd14b02df0192bded4caffected · git
    • 4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 and later · before 92803b826e40e49a5e8a6e208f4b4574e9d19426affected · git
    • 4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 and later · before 0393f85c3241c19ba8550f04a812e7d19f6b3082affected · git
    • 4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 and later · before 11709573cc4e48dc34c80fc7ab9ce5b159e29695affected · git
    • before 4.13not affected · semver
    • 6.1.191 and later · up to and including 6.1.*not affected · semver
    • 6.6.160 and later · up to and including 6.6.*not affected · semver
    • 6.12.113 and later · up to and including 6.12.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-124.31.1.el10_16.12.0-124.31.1.el10_1
AlmaLinux:10kernel-docbefore 6.12.0-124.31.1.el10_16.12.0-124.31.1.el10_1
AlmaLinux:8bpftoolbefore 4.18.0-553.104.1.el8_104.18.0-553.104.1.el8_10
AlmaLinux:8kernelbefore 4.18.0-553.104.1.el8_104.18.0-553.104.1.el8_10
AlmaLinux:8kernel-abi-stablelistsbefore 4.18.0-553.104.1.el8_104.18.0-553.104.1.el8_10
AlmaLinux:8kernel-corebefore 4.18.0-553.104.1.el8_104.18.0-553.104.1.el8_10
AlmaLinux:8kernel-cross-headersbefore 4.18.0-553.104.1.el8_104.18.0-553.104.1.el8_10
AlmaLinux:8kernel-debugbefore 4.18.0-553.104.1.el8_104.18.0-553.104.1.el8_10
AlmaLinux:8kernel-debug-corebefore 4.18.0-553.104.1.el8_104.18.0-553.104.1.el8_10
AlmaLinux:8kernel-debug-develbefore 4.18.0-553.104.1.el8_104.18.0-553.104.1.el8_10
AlmaLinux:8kernel-debug-modulesbefore 4.18.0-553.104.1.el8_104.18.0-553.104.1.el8_10
AlmaLinux:8kernel-debug-modules-extrabefore 4.18.0-553.104.1.el8_104.18.0-553.104.1.el8_10
AlmaLinux:8kernel-develbefore 4.18.0-553.104.1.el8_104.18.0-553.104.1.el8_10
AlmaLinux:8kernel-docbefore 4.18.0-553.104.1.el8_104.18.0-553.104.1.el8_10
AlmaLinux:8kernel-headersbefore 4.18.0-553.104.1.el8_104.18.0-553.104.1.el8_10
AlmaLinux:8kernel-modulesbefore 4.18.0-553.104.1.el8_104.18.0-553.104.1.el8_10
AlmaLinux:8kernel-modules-extrabefore 4.18.0-553.104.1.el8_104.18.0-553.104.1.el8_10
AlmaLinux:8kernel-rtbefore 4.18.0-553.104.1.rt7.445.el8_104.18.0-553.104.1.rt7.445.el8_10
AlmaLinux:8kernel-rt-corebefore 4.18.0-553.104.1.rt7.445.el8_104.18.0-553.104.1.rt7.445.el8_10
AlmaLinux:8kernel-rt-debugbefore 4.18.0-553.104.1.rt7.445.el8_104.18.0-553.104.1.rt7.445.el8_10
AlmaLinux:8kernel-rt-debug-corebefore 4.18.0-553.104.1.rt7.445.el8_104.18.0-553.104.1.rt7.445.el8_10
AlmaLinux:8kernel-rt-debug-develbefore 4.18.0-553.104.1.rt7.445.el8_104.18.0-553.104.1.rt7.445.el8_10
AlmaLinux:8kernel-rt-debug-modulesbefore 4.18.0-553.104.1.rt7.445.el8_104.18.0-553.104.1.rt7.445.el8_10
AlmaLinux:8kernel-rt-debug-modules-extrabefore 4.18.0-553.104.1.rt7.445.el8_104.18.0-553.104.1.rt7.445.el8_10

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2025-40156Nov 12, 2025 · PM / devfreq: mtk-cci: Fix potential error pointer dereference in probe()
    0Monitor
  • ← EarlierCVE-2025-40157Nov 12, 2025 · EDAC/i10nm: Skip DIMM enumeration on a disabled memory controller
    0Monitor
  • Later →CVE-2025-40159Nov 12, 2025 · xsk: Harden userspace-supplied xdp_desc validation
    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 Linux0393f85c3241c19ba8550f04a812e7d19f6b3082Vendor (CNA)
Linux Linux11709573cc4e48dc34c80fc7ab9ce5b159e29695Vendor (CNA)
Linux Linux423895685f367b5a0a956bd14b02df0192bded4cVendor (CNA)
Linux Linux4549ce1057363c8dc072f40c6aa591c279eafed2Vendor (CNA)
Linux Linux92803b826e40e49a5e8a6e208f4b4574e9d19426Vendor (CNA)
azl3 kernel 6.6.152.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
almalinux:kernel5.14.0-611.30.1.el9_7 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k5.14.0-611.30.1.el9_7 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-core5.14.0-611.30.1.el9_7 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug5.14.0-611.30.1.el9_7 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-core5.14.0-611.30.1.el9_7 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel5.14.0-611.30.1.el9_7 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched5.14.0-611.30.1.el9_7 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules5.14.0-611.30.1.el9_7 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-core5.14.0-611.30.1.el9_7 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra5.14.0-611.30.1.el9_7 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-abi-stablelists6.12.0-124.31.1.el10_1 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-doc6.12.0-124.31.1.el10_1 · AlmaLinux:10Package registry (OSV)
debian:linux6.12.113-1 · Debian:13Package registry (OSV)
debian:linux6.17.6-1 · Debian:14Package registry (OSV)
debian:linux-6.126.12.113-1~deb12u1 · Debian:12Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-64k-debug-devel0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-64k-debug-devel-matched0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-64k-debuginfo0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-64k-devel0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-64k-devel-matched0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-debug-debuginfo0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-debug-devel0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)

+5

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

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

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
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/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.

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 (4 more)

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

All records