CVE-2026-40896
OpenProject has Cross-Project Meeting Agenda Item Injection via Unscoped Section Lookup
Description
OpenProject is open-source, web-based project management software. Prior to version 17.3.0, a user with `manage_agendas` permission in any project can inject agenda items into meetings belonging to any other project on the instance — even projects they have no access to. No knowledge of the target project, meeting, or victim is required; the attacker can blindly spray items into every meeting on the instance by iterating sequential section IDs. Version 17.3.0 patches the issue.
INFO
Published Date :
April 20, 2026, 4:16 p.m.
Last Modified :
April 23, 2026, 1:45 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update OpenProject to version 17.3.0 or later.
- Verify user permissions for agenda management.
- Apply the vendor-supplied patch.
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-2026-40896.
| URL | Resource |
|---|---|
| https://github.com/opf/openproject/commit/8f693a1f35d0a84bb69af78fb6925f74329ae4fe | Patch |
| https://github.com/opf/openproject/security/advisories/GHSA-hh5p-gwf8-h245 | Exploit Mitigation Vendor Advisory |
| https://github.com/opf/openproject/security/advisories/GHSA-hh5p-gwf8-h245 | Exploit Mitigation Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-40896 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-2026-40896
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-2026-40896 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-40896 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.
-
Initial Analysis by [email protected]
Apr. 23, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N Added CPE Configuration OR *cpe:2.3:a:openproject:openproject:*:*:*:*:*:*:*:* versions up to (excluding) 17.3.0 Added Reference Type GitHub, Inc.: https://github.com/opf/openproject/commit/8f693a1f35d0a84bb69af78fb6925f74329ae4fe Types: Patch Added Reference Type CISA-ADP: https://github.com/opf/openproject/security/advisories/GHSA-hh5p-gwf8-h245 Types: Exploit, Mitigation, Vendor Advisory Added Reference Type GitHub, Inc.: https://github.com/opf/openproject/security/advisories/GHSA-hh5p-gwf8-h245 Types: Exploit, Mitigation, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Apr. 20, 2026
Action Type Old Value New Value Added Reference https://github.com/opf/openproject/security/advisories/GHSA-hh5p-gwf8-h245 -
New CVE Received by [email protected]
Apr. 20, 2026
Action Type Old Value New Value Added Description OpenProject is open-source, web-based project management software. Prior to version 17.3.0, a user with `manage_agendas` permission in any project can inject agenda items into meetings belonging to any other project on the instance — even projects they have no access to. No knowledge of the target project, meeting, or victim is required; the attacker can blindly spray items into every meeting on the instance by iterating sequential section IDs. Version 17.3.0 patches the issue. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N Added CWE CWE-367 Added CWE CWE-639 Added Reference https://github.com/opf/openproject/commit/8f693a1f35d0a84bb69af78fb6925f74329ae4fe Added Reference https://github.com/opf/openproject/security/advisories/GHSA-hh5p-gwf8-h245