Time-of-check Time-of-use (TOCTOU) Affecting python3-perf package, versions *


Severity

Recommended
0.0
high
0
10

Based on CentOS security rating.

Threat Intelligence

EPSS
0.13% (3rd percentile)

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  • Snyk IDSNYK-CENTOS10-PYTHON3PERF-19834169
  • published16 Sept 2026
  • disclosed11 Sept 2026

Introduced: 11 Sep 2026

NewCVE-2026-89487  (opens in a new tab)
CWE-367  (opens in a new tab)

How to fix?

There is no fixed version for Centos:10 python3-perf.

NVD Description

Note: Versions mentioned in the description apply only to the upstream python3-perf package and not the python3-perf package as distributed by Centos. See How to fix? for Centos:10 relevant fixed versions and status.

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

openvswitch: only skb_tx_error() a packet we are about to drop

queue_userspace_packet() borrows the packet skb -- it only copies it into a private netlink message (user_skb) and does not own it; on return do_execute_actions() keeps forwarding it through the flow's remaining actions. Its error path nevertheless calls skb_tx_error(skb), which via skb_zcopy_clear() does skb_shinfo(skb)->flags &= ~SKBFL_ALL_ZEROCOPY, stripping SKBFL_SHARED_FRAG from that live skb (skb_tx_error()'s kerneldoc says "skb must be freed afterwards").

For a MSG_ZEROCOPY skb carrying page-cache frags, SKBFL_SHARED_FRAG is what makes esp_input() skb_cow_data() before in-place AEAD; once it is stripped a later local ESP-in-UDP delivery decrypts in place over pages the sender does not own -- an unprivileged page-cache write (the "Fragnesia" primitive). do_execute_actions() ignores output_userspace()'s return value, so any action after a failed USERSPACE upcall inherits the stripped skb.

Move the skb_tx_error() to the flow-miss drop path - the "default" branch of ovs_dp_process_packet()'s switch(error), before kfree_skb().

The call has been here since commit 36d5fe6a0007 ("core, nfqueue, openvswitch: Orphan frags in skb_zerocopy and handle errors") but was harmless until esp_input() began relying on SKBFL_SHARED_FRAG to gate in-place decrypt; only then did stripping it on a still-forwarded skb become a page-cache write primitive.

CVSS Base Scores

version 3.1