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VulnerabilityPublished Updated

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

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in f49ed02fd8c98da823fdd7b00d64a8cc1d1883ac : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in f49ed02fd8c98da823fdd7b00d64a8cc1d1883ac, ecf69d4b43370c587e48d4d70289dbdb7e039d4d, cee6688e5731c0591643521716d1a1a5c1a98bf8 +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 15 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ cc4e3835eff474aa274d6e1d18f69d9d296d3b76, < f49ed02fd8c98da823fdd7b00d64a8cc1d1883ac
Fixed in
  • f49ed02fd8c98da823fdd7b00d64a8cc1d1883ac
LinuxLinuxAffected
  • ≥ cc4e3835eff474aa274d6e1d18f69d9d296d3b76, < ecf69d4b43370c587e48d4d70289dbdb7e039d4d
Fixed in
  • ecf69d4b43370c587e48d4d70289dbdb7e039d4d
LinuxLinuxAffected
  • ≥ cc4e3835eff474aa274d6e1d18f69d9d296d3b76, < cee6688e5731c0591643521716d1a1a5c1a98bf8
Fixed in
  • cee6688e5731c0591643521716d1a1a5c1a98bf8
LinuxLinuxAffected
  • ≥ cc4e3835eff474aa274d6e1d18f69d9d296d3b76, < 54292b167466cdf42176b7b6f01da66c184deb12
Fixed in
  • 54292b167466cdf42176b7b6f01da66c184deb12
LinuxLinuxAffected
  • ≥ cc4e3835eff474aa274d6e1d18f69d9d296d3b76, < 9075efb9b2c1d9d7a8285c937b64aa93ca0c41b7
Fixed in
  • 9075efb9b2c1d9d7a8285c937b64aa93ca0c41b7
LinuxLinuxAffected
  • =5.9
Fixed in–

Description

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.

References

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