CVE-2026-72724
Discourse: Private Chat Threat Message Disclosure via Chat Onebox Channel/Threat ID Mismatch
Description
Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, plugins/chat/lib/chat/onebox_handler.rb resolves Chat::Thread by route thread_id independently of the route channel_id before checking whether the user can preview the selected chat channel. An authenticated user can pair a public channel ID with a private thread ID in a /onebox.json request and obtain private thread message content. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.
INFO
Published Date :
Aug. 10, 2026, 4:19 p.m.
Last Modified :
Aug. 10, 2026, 4:19 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-72724
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 | [email protected] |
Solution
- Update Discourse to version 2026.1.6 or later.
- Apply patches for versions 2026.5.2, 2026.6.1, or 2026.7.0.
- Ensure chat channel and thread IDs are validated together.
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-2026-72724.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-72724 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-2026-72724
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-2026-72724 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-72724 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]
Aug. 10, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'discourse', 'product': 'discourse', 'versions': [{'status': 'affected', 'version': '< 2026.1.6'}, {'status': 'affected', 'version': '>= 2026.5.0-latest, < 2026.5.2'}, {'status': 'affected', 'version': '>= 2026.6.0-latest, < 2026.6.1'}, {'status': 'affected', 'version': '>= 2026.7.0-latest, < 2026.7.0'}]}] Added Description Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, plugins/chat/lib/chat/onebox_handler.rb resolves Chat::Thread by route thread_id independently of the route channel_id before checking whether the user can preview the selected chat channel. An authenticated user can pair a public channel ID with a private thread ID in a /onebox.json request and obtain private thread message content. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Added CWE CWE-639 Added Reference https://github.com/discourse/discourse/commit/1276d7032af8803956c74ae87ccfd976938dcd75 Added Reference https://github.com/discourse/discourse/commit/45ab6d54076de9ca4965888974d4416d5b48e83c Added Reference https://github.com/discourse/discourse/commit/49efe1d7f098f2ce7301908815a211cc9248270f Added Reference https://github.com/discourse/discourse/commit/dc54846f0754799591717b6018343e49524e41ce Added Reference https://github.com/discourse/discourse/pull/42091 Added Reference https://github.com/discourse/discourse/pull/42092 Added Reference https://github.com/discourse/discourse/pull/42093 Added Reference https://github.com/discourse/discourse/pull/42094 Added Reference https://github.com/discourse/discourse/security/advisories/GHSA-8g98-fvfc-9w48