Tor before 0.4.9.12 interprets the CC_RESPONSE extension even when CC_REQUEST was not sent, which allows remote attackers to cause a denial of service (crash) because of corrupted congestion-control state. This is TROVE-2026-032.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact Low

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.0026.

Exploitation none

Automatable no

Technical Impact partial

Affected Vendors & Products

No data.

No data.

No data.

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No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://gitlab.com/torproject/tor/-/commit/10d4b8ffefa7c00aab2b631ed7e7f15e42cd012d cve-icon cve-icon
https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.12/ChangeLog cve-icon cve-icon
History

Wed, 09 Sep 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 09 Sep 2026 04:45:00 +0000

Type Values Removed Values Added
Title Tor Pre‑0.4.9.12 Unchecked CC_RESPONSE Causes Denial of Service

Wed, 09 Sep 2026 01:45:00 +0000

Type Values Removed Values Added
Description Tor before 0.4.9.12 interprets the CC_RESPONSE extension even when CC_REQUEST was not sent, which allows remote attackers to cause a denial of service (crash) because of corrupted congestion-control state. This is TROVE-2026-032.
Weaknesses CWE-669
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-09-09T18:18:39.270Z

Reserved: 2026-09-09T01:29:45.866Z

Link: CVE-2026-87724

cve-icon Vulnrichment

Updated: 2026-09-09T18:18:32.815Z

cve-icon NVD

Status : Deferred

Published: 2026-09-09T02:16:57.670

Modified: 2026-09-09T19:17:50.287

Link: CVE-2026-87724

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-09T04:30:05Z

Weaknesses