---
id: CVE-2026-77638
title: >-
  Tor before 0.4.9.11 is prone to a race condition where in just the right
  circumstances a rendezvous point could man-in-the-middle (impersonate) the
  onion service that the client was trying to reach.
summary: >-
  Tor before 0.4.9.11 is prone to a race condition where in just the right
  circumstances a rendezvous point could man-in-the-middle (impersonate) the
  onion service that the client was trying to reach.
severity: high
cvss: 8.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L'
cwe:
  - CWE-362
vendor: torproject
product: tor
affected:
  - tor < 0.4.9.11
patched:
  - tor 0.4.9.11
published: '2026-08-20'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T14:08:23.407'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-77638'
references:
  - url: 'https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.11/ChangeLog'
    label: cve@mitre.org
tags:
  - nvd
epss: 0.00299
epssPercentile: 0.20111
ingestedAt: '2026-09-16T14:57:28.002Z'
---

## Overview

Tor before 0.4.9.11 is prone to a race condition where in just the right circumstances a rendezvous point could man-in-the-middle (impersonate) the onion service that the client was trying to reach.

## Affected

- `tor < 0.4.9.11`

## Remediation

Upgrade past the affected range:

- `tor 0.4.9.11`