# CVE-2026-80977

## Summary

- **CVE ID:** CVE-2026-80977
- **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 14, 2026

## Description

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

net: skbuff: don't touch shared zerocopy state in skb_tx_error()

skb_tx_error() completes the zerocopy uarg and clears
SKBFL_ALL_ZEROCOPY, and skb_zcopy_downgrade_managed() clears
SKBFL_MANAGED_FRAG_REFS. Both live in skb_shinfo(), which every clone
shares, while the caller only owns the reference it is about to drop.
Through a clone it tells the producer its pages are free and drops
SKBFL_SHARED_FRAG for an skb that is still in flight.

Open vSwitch reaches this with a non-last OVS_ACTION_ATTR_RECIRC:
clone_execute() sends a skb_clone() into ovs_dp_process_packet() while
do_execute_actions() keeps forwarding the original, and skb_clone()
does not privatise the frags here -- skb_orphan_frags() returns early
on SKBFL_DONT_ORPHAN. A flow miss on the clone then strips the marker
from the packet still being forwarded, and a later local ESP delivery
decrypts in place over frags it does not own privately.

Skip it for a cloned skb. Nothing is lost: skb_release_data() clears
the zerocopy state once the last reference to the shared data goes.

## Affected Products

- Linux — Linux (25121173f7b1e4ac3fc692df6e7b8c52ec36abba)
- Linux — Linux (3.8)
- Linux — Linux (0)
- Linux — Linux (6.12.109)
- Linux — Linux (6.18.50)
- Linux — Linux (7.2.4)
- Linux — Linux (7.3-rc1)
- Linux — Linux (5.10.270)
- Linux — Linux (5.15.221)
- Linux — Linux (6.1.188)
- Linux — Linux (6.6.157)

## References

- [CNA](https://git.kernel.org/stable/c/15aa81b390d401abf4b8211042470e9e92e3b7fb)
- [CNA](https://git.kernel.org/stable/c/288f9970670841044ab030104fa6b6ed159949d0)
- [CNA](https://git.kernel.org/stable/c/0370da114a9bc044e248b85c6809d1b5e0c1f7f9)
- [CNA](https://git.kernel.org/stable/c/f66bdb1cc0fcd227a062378f8be0b5873aa5600a)
- [CNA](https://git.kernel.org/stable/c/6493165034bca14033bf49c9cec7b45e97a91497)
- [CNA](https://git.kernel.org/stable/c/b4452349dcf4d561e13be768d5d278de58248930)
- [CNA](https://git.kernel.org/stable/c/363c4252ffc473a0203e91b83ede5519dfb8bd07)
- [CNA](https://git.kernel.org/stable/c/6ec22afc82a3cae07ade0a6ec361ae2532128ff5)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.13%
- **EPSS Percentile:** 2.9

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._