---
id: CVE-2026-77642
title: "tor before 0.4.9.9 was prone to an\_out-of-bounds write when parsing a consensus or  detached signature with unexpected signature digest type"
summary: "tor before 0.4.9.9 was prone to an\_out-of-bounds write when parsing a consensus or  detached signature with unexpected signature digest type. Impact  is minor for most Tor roles, but potentially major for directory   authorities. This is…"
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:H'
cwe:
  - CWE-787
vendor: torproject
product: tor
affected:
  - tor < 0.4.9.9
patched:
  - tor 0.4.9.9
published: '2026-08-20'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T18:11:10.597'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-77642'
references:
  - url: 'https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.9/ChangeLog'
    label: cve@mitre.org
tags:
  - nvd
epss: 0.00353
epssPercentile: 0.26315
ingestedAt: '2026-09-08T19:08:49.591Z'
---

## Overview

tor before 0.4.9.9 was prone to an out-of-bounds write when parsing a consensus or  detached signature with unexpected signature digest type. Impact  is minor for most Tor roles, but potentially major for directory   authorities. This is TROVE-2026-019.

## Affected

- `tor < 0.4.9.9`

## Remediation

Upgrade past the affected range:

- `tor 0.4.9.9`