CVE-2026-87724
Tor Congestion Control Denial of Service Vulnerability
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.
INFO
Published Date :
Sept. 9, 2026, 2:16 a.m.
Last Modified :
Sept. 9, 2026, 2:16 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-87724
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 8254265b-2729-46b6-b9e3-3dfca2d5bfca | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Tor to version 0.4.9.12 or later.
- Ensure proper congestion-control state management.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-87724.
| URL | Resource |
|---|---|
| https://gitlab.com/torproject/tor/-/commit/10d4b8ffefa7c00aab2b631ed7e7f15e42cd012d | |
| https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.12/ChangeLog |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-87724 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-87724
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-87724 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-87724 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Sep. 09, 2026
Action Type Old Value New Value 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. Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H Added CWE CWE-669 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/87xxx/CVE-2026-87724.json">CVE-2026-87724</a> Added Reference https://gitlab.com/torproject/tor/-/commit/10d4b8ffefa7c00aab2b631ed7e7f15e42cd012d Added Reference https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.12/ChangeLog