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NVD / CVE Program· CNA Linux

CVE-2026-72405: net: udp_tunnel: prevent double queueing in udp_tunnel_nic_device_sync

HighCVSS 7.8 · v3.1—No exploit Fix available

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 54292b167466cdf42176b7b6f01da66c184deb12, 9075efb9b2c1d9d7a8285c937b64aa93ca0c41b7, cee6688e5731c0591643521716d1a1a5c1a98bf8; 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 54292b167466cdf42176b7b6f01da66c184deb12, 9075efb9b2c1d9d7a8285c937b64aa93ca0c41b7, cee6688e5731c0591643521716d1a1a5c1a98bf8; 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: net: udp_tunnel: prevent double queueing in udp_tunnel_nic_device_sync Yue Sun reported a use-after-free and debugobjects warning in udp_tunnel_nic_device_sync_work() during concurrent device operations. The workqueue core clears the internal pending bit before invoking the worker. At that point, a concurrent thread can queue the work again. When the already running worker eventually clears the work_pending flag to 0, it mistakenly clears the flag for the newly queued instance. udp_tunnel_nic_unregister() then observes work_pending as 0 and frees the structure while the second work item is still active in the queue, leading to UAF. Fix this by returning early in udp_tunnel_nic_device_sync() if work_pending is already set, preventing redundant work queueing.

Published
Aug 15, 2026
Updated
Oct 30, 2026
EPSS
0.1% · 3th 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
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-2026-72405

When you'll hear from us

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  • 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.

—

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

    • 5.9affected
    • cc4e3835eff474aa274d6e1d18f69d9d296d3b76 and later · before d59d3b19e1cd1a01a6db59705327387a30aed153affected · git
    • cc4e3835eff474aa274d6e1d18f69d9d296d3b76 and later · before f49ed02fd8c98da823fdd7b00d64a8cc1d1883acaffected · git
    • cc4e3835eff474aa274d6e1d18f69d9d296d3b76 and later · before cee6688e5731c0591643521716d1a1a5c1a98bf8affected · git
    • cc4e3835eff474aa274d6e1d18f69d9d296d3b76 and later · before 9075efb9b2c1d9d7a8285c937b64aa93ca0c41b7affected · git
    • cc4e3835eff474aa274d6e1d18f69d9d296d3b76 and later · before 54292b167466cdf42176b7b6f01da66c184deb12affected · git
    • cc4e3835eff474aa274d6e1d18f69d9d296d3b76 and later · before ecf69d4b43370c587e48d4d70289dbdb7e039d4daffected · git
    • before 5.9not 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

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:13linuxbefore 6.12.100-16.12.100-1
Debian:14linuxbefore 7.1.5-17.1.5-1

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-2026-72402Aug 15, 2026 · bpf: Mask pseudo pointer values in verifier logs
    0Monitor
  • ← EarlierCVE-2026-72404Aug 15, 2026 · tipc: fix UAF in cleanup_bearer() due to premature dst_cache_destroy()
    31Monitor
  • Later →CVE-2026-72406Aug 15, 2026 · net: sungem: fix probe error cleanup
    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 Linux54292b167466cdf42176b7b6f01da66c184deb12Vendor (CNA)
Linux Linux9075efb9b2c1d9d7a8285c937b64aa93ca0c41b7Vendor (CNA)
Linux Linuxcee6688e5731c0591643521716d1a1a5c1a98bf8Vendor (CNA)
Linux Linuxd59d3b19e1cd1a01a6db59705327387a30aed153Vendor (CNA)
Linux Linuxecf69d4b43370c587e48d4d70289dbdb7e039d4dVendor (CNA)
Linux Linuxf49ed02fd8c98da823fdd7b00d64a8cc1d1883acVendor (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)
azl3 kernel 6.6.159.1-1 on Azure Linux 3.06.6.161.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.12.100-1 · Debian:13Package 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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Not on record for this CVE: patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

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.

References

Show all references (5 more)

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

All records