Linux Kernel up to 7.1.9 ovpn use after free

Summaryinfo

A vulnerability classified as very critical has been found in Linux Kernel up to 7.1.9. Affected by this issue is some unknown functionality of the component ovpn. Performing a manipulation results in use after free. This vulnerability is known as CVE-2026-80753. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.1.9. It has been classified as very critical. This affects some unknown processing of the component ovpn. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: ovpn: run deferred work on a module-owned workqueue ovpn queues several work items whose callbacks execute module text. These works currently run on the global system workqueues, so module exit has no driver-owned drain point that guarantees the callbacks have fully returned before the module text can be freed. Object references protect the objects used by the callbacks, but they do not prove that a workqueue function has returned. In particular, a worker can drop the final reference that unblocks device teardown while it is still executing ovpn code. Add a module-owned workqueue and queue all ovpn work items on it. During module exit, unregister rtnl and netlink first, flush the workqueue so ordinary ovpn workers finish, run the final RCU barrier, and destroy the workqueue last. This keeps the workqueue available for cleanup work queued from RCU callbacks, while ensuring no ovpn work item can outlive the module text. The per-device delayed keepalive work remains explicitly disabled during netdev teardown (disable_delayed_work_sync in ndo_uninit), since flush_workqueue does not flush delayed work that is still only pending on its timer.

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-80753 since 08/26/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/03/2026).

Upgrading to version 7.1.10 eliminates this vulnerability. Applying the patch bbe81f40582d451ac849b20707784220f33a23bd/e9714db8041763f59dde152c812b96b3de05c6d9 is able to eliminate this problem.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3
• 7.1.4
• 7.1.5
• 7.1.6
• 7.1.7
• 7.1.8
• 7.1.9

License

• open-source

Website

• Vendor: https://www.kernel.org/

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