CVE-2026-87724: CWE-669 Incorrect Resource Transfer Between Spheres in torprject Tor
A vulnerability in Tor before version 0.4.9.12 allows remote attackers to cause a denial of service by crashing the application. This occurs because Tor interprets the CC_RESPONSE extension even when the CC_REQUEST extension was not sent, leading to corrupted congestion-control state.
AI Analysis
Technical Summary
CVE-2026-87724 is a vulnerability in the Tor software where versions prior to 0.4.9.12 improperly handle the CC_RESPONSE extension without a preceding CC_REQUEST. This flaw causes corrupted congestion-control state, which can be exploited remotely to trigger a denial of service (crash). The issue is categorized under CWE-669 (Incorrect Resource Transfer Between Spheres).
Potential Impact
The vulnerability allows remote attackers to cause a denial of service by crashing the Tor process due to corrupted congestion-control state. There is no indication of confidentiality or availability impact beyond denial of service, and no known exploits in the wild have been reported.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary workaround has been documented at this time.
CVE-2026-87724: CWE-669 Incorrect Resource Transfer Between Spheres in torprject Tor
Description
A vulnerability in Tor before version 0.4.9.12 allows remote attackers to cause a denial of service by crashing the application. This occurs because Tor interprets the CC_RESPONSE extension even when the CC_REQUEST extension was not sent, leading to corrupted congestion-control state.
CVSS v3.1
Score 6.5medium
Affected software
pkg:github/torproject/torRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-87724 is a vulnerability in the Tor software where versions prior to 0.4.9.12 improperly handle the CC_RESPONSE extension without a preceding CC_REQUEST. This flaw causes corrupted congestion-control state, which can be exploited remotely to trigger a denial of service (crash). The issue is categorized under CWE-669 (Incorrect Resource Transfer Between Spheres).
Potential Impact
The vulnerability allows remote attackers to cause a denial of service by crashing the Tor process due to corrupted congestion-control state. There is no indication of confidentiality or availability impact beyond denial of service, and no known exploits in the wild have been reported.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary workaround has been documented at this time.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2026-09-09T01:29:45.866Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6aa0b867acd9273b4989b578
Added to database: 09/09/2026, 01:37:43 UTC
Last enriched: 09/09/2026, 01:52:39 UTC
Last updated: 09/09/2026, 02:24:58 UTC
Views: 5
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