CVE-2026-87724 Details
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.
A denial-of-service vulnerability has been identified in Tor versions prior to 0.4.9.12. The issue arises because the software incorrectly processes the CC_RESPONSE extension without the corresponding CC_REQUEST being sent. This misinterpretation can lead to a crash by corrupting the congestion-control state, causing a disruption in service.
Users can upgrade to Tor version 0.4.9.12 or later to address this vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Sep 9, 2026CISA-ADP
Assessed Sep 9, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://gitlab.com/torproject/tor/-/commit/10d4b8ffefa7c00aab2b631ed7e7f15e42cd012d | [email protected] | Source CodeVendor |
| https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.12/ChangeLog | [email protected] | Release NotesVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-669 | Incorrect Resource Transfer Between Spheres | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Tor | < 0.4.9.12 |
CPE
Remediation
| |
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 9, 2026 | CVE Modified | CISA-ADP |
| Sep 9, 2026 | New CVE Received | [email protected] |