Tor Project 0.4.9.9/0.4.9.11 state issue

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.9$5k-$25k0.45+

Summaryinfo

A vulnerability was found in Tor Project Tor and classified as critical. The impacted element is an unknown function. Executing a manipulation can lead to state issue. This vulnerability appears as CVE-2026-87724. The attack may be performed from remote. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Tor Project Tor and classified as critical. This vulnerability affects an unknown code. The manipulation with an unknown input leads to a state issue vulnerability. The CWE definition for the vulnerability is CWE-371. As an impact it is known to affect availability. CVE summarizes:

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.

The advisory is shared for download at gitlab.torproject.org. This vulnerability was named CVE-2026-87724 since 09/09/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 09/09/2026).

Upgrading to version 0.4.9.12 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Vendor

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.0
VulDB Meta Temp Score: 6.9

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.5
CNA Vector (MITRE): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: State issue
CWE: CWE-371
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Tor 0.4.9.12

Timelineinfo

09/09/2026 Advisory disclosed
09/09/2026 +0 days CVE reserved
09/09/2026 +0 days VulDB entry created
09/09/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: gitlab.torproject.org
Status: Confirmed

CVE: CVE-2026-87724 (🔒)
GCVE (CVE): GCVE-0-2026-87724
GCVE (VulDB): GCVE-100-401188

Entryinfo

Created: 09/09/2026 04:03
Changes: 09/09/2026 04:03 (63)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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