CVE-2026-77587

Received Received - Intake

Use-After-Free in Tor Network Client

Publication date: 2026-08-20

Last updated on: 2026-08-20

Assigner: MITRE

Description

Tor before 0.4.9.11 is prone to a use-after-free (and potential double free) of a conflux object when a recovery leg revives a conflux set whose last linked leg has already been closed. A malicious exit node could use this to crash a client. This is TROVE-2026-026.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-08-20

Last Modified

2026-08-20

Generated

2026-08-21

AI Q&A

2026-08-21

EPSS Evaluated

N/A

NVD

CVE-2026-77587

EUVD

EUVD-2026-63593

Affected Vendors & Products

Vendor	Product	Version / Range
tor_project	tor	to 0.4.9.11 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-911	The product uses a reference count to manage a resource, but it does not update or incorrectly updates the reference count.

Attack-Flow Graph

Executive Summary

This vulnerability is a use-after-free issue in Tor before version 0.4.9.11. It occurs when a recovery leg revives a conflux set whose last linked leg has already been closed, leading to a potential double free of a conflux object. A malicious exit node could exploit this to crash a client.

Impact Analysis

If you are a Tor user, this vulnerability could allow a malicious exit node to crash your client. This may disrupt your anonymity while using Tor, as the crash could expose your activity or force a restart.

Mitigation Strategies

Update Tor to version 0.4.9.11 or later to address the use-after-free issue in conflux objects.

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