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NVD / CVE Program· CNA Linux

CVE-2025-40215: xfrm: delete x->tunnel as we delete x

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: 0.15% (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 0da961fa46da1b37ef868d9b603bd202136f8f8e, 1b28a7fae0128fa140a7dccd995182ff6cd1c67b, 4b2c17d0f9be8b58bb30468bc81a4b61c985b04e; azl3 kernel 6.6.119.3-3 on Azure Linux 3.0 6.6.121.1-1.

Low priority for now. Upgrade to Linux Linux 0da961fa46da1b37ef868d9b603bd202136f8f8e, 1b28a7fae0128fa140a7dccd995182ff6cd1c67b, 4b2c17d0f9be8b58bb30468bc81a4b61c985b04e; azl3 kernel 6.6.119.3-3 on Azure Linux 3.0 6.6.121.1-1 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: xfrm: delete x->tunnel as we delete x The ipcomp fallback tunnels currently get deleted (from the various lists and hashtables) as the last user state that needed that fallback is destroyed (not deleted). If a reference to that user state still exists, the fallback state will remain on the hashtables/lists, triggering the WARN in xfrm_state_fini. Because of those remaining references, the fix in commit f75a2804da39 ("xfrm: destroy xfrm_state synchronously on net exit path") is not complete. We recently fixed one such situation in TCP due to defered freeing of skbs (commit 9b6412e6979f ("tcp: drop secpath at the same time as we currently drop dst")). This can also happen due to IP reassembly: skbs with a secpath remain on the reassembly queue until netns destruction. If we can't guarantee that the queues are flushed by the time xfrm_state_fini runs, there may still be references to a (user) xfrm_state, preventing the timely deletion of the corresponding fallback state. Instead of chasing each instance of skbs holding a secpath one by one, this patch fixes the issue directly within xfrm, by deleting the fallback state as soon as the last user state depending on it has been deleted. Destruction will still happen when the final reference is dropped. A separate lockdep class for the fallback state is required since we're going to lock x->tunnel while x is locked.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Dec 4, 2025
Updated
Oct 19, 2026
EPSS
0.1% · 4th percentile
CWE
—

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
partial

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.

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  • A fix has been released

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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

    • 2.6.29affected
    • 9d4139c76905833afcb77fe8ccc17f302a0eb9ab and later · before 1b28a7fae0128fa140a7dccd995182ff6cd1c67baffected · git
    • 9d4139c76905833afcb77fe8ccc17f302a0eb9ab and later · before 4b2c17d0f9be8b58bb30468bc81a4b61c985b04eaffected · git
    • 9d4139c76905833afcb77fe8ccc17f302a0eb9ab and later · before 0da961fa46da1b37ef868d9b603bd202136f8f8eaffected · git
    • 9d4139c76905833afcb77fe8ccc17f302a0eb9ab and later · before d0e0d1097118461463b76562c7ebaabaa5b90b13affected · git
    • 9d4139c76905833afcb77fe8ccc17f302a0eb9ab and later · before dc3636912d41770466543623cb76e7b88fdb42c7affected · git
    • 9d4139c76905833afcb77fe8ccc17f302a0eb9ab and later · before b441cf3f8c4b8576639d20c8eb4aa32917602ecdaffected · git
    • before 2.6.29not affected · semver
    • 5.10.248 and later · up to and including 5.10.*not affected · semver
    • 5.15.198 and later · up to and including 5.15.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:11linuxbefore 5.10.249-15.10.249-1
Debian:12linuxbefore 6.1.162-16.1.162-1
Debian:13linuxbefore 6.12.63-16.12.63-1
Debian:14linuxbefore 6.16.3-16.16.3-1
openSUSE:Leap 16.0dtb-aarch64before 6.12.0-160000.9.16.12.0-160000.9.1
openSUSE:Leap 16.0kernel-64kbbefore 6.12.0-160000.9.16.12.0-160000.9.1
openSUSE:Leap 16.0kernel-azurebefore 6.12.0-160000.9.16.12.0-160000.9.1
openSUSE:Leap 16.0kernel-defaultbefore 6.12.0-160000.9.16.12.0-160000.9.1
openSUSE:Leap 16.0kernel-default-basebefore 6.12.0-160000.9.1.160000.2.66.12.0-160000.9.1.160000.2.6
openSUSE:Leap 16.0kernel-docsbefore 6.12.0-160000.9.16.12.0-160000.9.1
openSUSE:Leap 16.0kernel-kvmsmallbefore 6.12.0-160000.9.16.12.0-160000.9.1
openSUSE:Leap 16.0kernel-obs-buildbefore 6.12.0-160000.9.16.12.0-160000.9.1
openSUSE:Leap 16.0kernel-obs-qabefore 6.12.0-160000.9.16.12.0-160000.9.1
openSUSE:Leap 16.0kernel-rtbefore 6.12.0-160000.9.16.12.0-160000.9.1
openSUSE:Leap 16.0kernel-sourcebefore 6.12.0-160000.9.16.12.0-160000.9.1
openSUSE:Leap 16.0kernel-symsbefore 6.12.0-160000.9.16.12.0-160000.9.1
openSUSE:Leap 16.0kernel-zfcpdumpbefore 6.12.0-160000.9.16.12.0-160000.9.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-defaultbefore 3.0.101-108.198.13.0.101-108.198.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-docsbefore 3.0.101-108.198.13.0.101-108.198.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-ec2before 3.0.101-108.198.13.0.101-108.198.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-sourcebefore 3.0.101-108.198.13.0.101-108.198.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-symsbefore 3.0.101-108.198.13.0.101-108.198.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-tracebefore 3.0.101-108.198.13.0.101-108.198.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-xenbefore 3.0.101-108.198.13.0.101-108.198.1

+12

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-2025-40213Nov 24, 2025 · Bluetooth: MGMT: fix crash in set_mesh_sync and set_mesh_complete
    31Monitor
  • ← EarlierCVE-2025-40214Dec 4, 2025 · af_unix: Initialise scc_index in unix_add_edge().
    31Monitor
  • Later →CVE-2025-40216Dec 4, 2025 · io_uring/rsrc: don't rely on user vaddr alignment
    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 Linux0da961fa46da1b37ef868d9b603bd202136f8f8eVendor (CNA)
Linux Linux1b28a7fae0128fa140a7dccd995182ff6cd1c67bVendor (CNA)
Linux Linux4b2c17d0f9be8b58bb30468bc81a4b61c985b04eVendor (CNA)
Linux Linuxb441cf3f8c4b8576639d20c8eb4aa32917602ecdVendor (CNA)
Linux Linuxd0e0d1097118461463b76562c7ebaabaa5b90b13Vendor (CNA)
Linux Linuxdc3636912d41770466543623cb76e7b88fdb42c7Vendor (CNA)
azl3 kernel 6.6.119.3-3 on Azure Linux 3.06.6.121.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.162-1 · Debian:12Package registry (OSV)
opensuse:dtb-aarch646.12.0-160000.9.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-64kb6.12.0-160000.9.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-azure6.12.0-160000.9.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-default6.12.0-160000.9.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-default-base6.12.0-160000.9.1.160000.2.6 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-docs6.12.0-160000.9.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-kvmsmall6.12.0-160000.9.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-obs-build6.12.0-160000.9.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-obs-qa6.12.0-160000.9.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-rt6.12.0-160000.9.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-source6.12.0-160000.9.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-syms6.12.0-160000.9.1 · openSUSE:Leap 16.0Package registry (OSV)
suse:kernel-64kb6.12.0-160000.9.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-azure6.12.0-160000.9.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)
suse:kernel-default3.0.101-108.198.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)
suse:kernel-default-base6.12.0-160000.9.1.160000.2.6 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-docs3.0.101-108.198.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)
suse:kernel-ec23.0.101-108.198.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)
suse:kernel-kvmsmall6.12.0-160000.9.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)
suse:kernel-rt6.12.0-160000.9.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-source3.0.101-108.198.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)
suse:kernel-syms3.0.101-108.198.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)

+2

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)

—

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.

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 (5 more)

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

All records