# CVE-2026-80991

## Summary

- **CVE ID:** CVE-2026-80991
- **Severity:** HIGH
- **CVSS Score:** 7.8 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
- **CWE:** N/A
- **Published:** Sep 11, 2026
- **Last Modified:** Sep 13, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:

net: ravb: serialize PTP clock teardown

ravb_ptp_interrupt() can race with ravb_ptp_stop() and pass the clock to
ptp_clock_event() while ptp_clock_unregister() is freeing it. This can
lead to a use-after-free.

Use READ_ONCE() and WRITE_ONCE() for lockless access to the clock pointer.
Atomically detach it with xchg() before disabling PTP interrupts, then
synchronize all IRQs which can invoke ravb_ptp_interrupt() before
unregistering the detached clock.

A handler which read the old pointer completes before the clock is
unregistered, while later handlers read NULL and skip the event.

## Affected Products

- Linux — Linux (a0d2f20650e81407d8e51ad2cbdc492861c74e9c)
- Linux — Linux (4.2)
- Linux — Linux (0)
- Linux — Linux (6.12.109)
- Linux — Linux (6.18.50)
- Linux — Linux (7.2.4)
- Linux — Linux (7.3-rc1)

## References

- [CNA](https://git.kernel.org/stable/c/695acb5534a9e366efb47b40c7487fc56488b09b)
- [CNA](https://git.kernel.org/stable/c/67a82e6f886beed0de8f8da08bb767e68fba952d)
- [CNA](https://git.kernel.org/stable/c/66b50c31419e7946e9aa325a468ad9b64c961a25)
- [CNA](https://git.kernel.org/stable/c/1cb9663789c5b7a12fcd419fcca6d6254c398252)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.16%
- **EPSS Percentile:** 5.4

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-17._