CVE-2026-40896

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.

CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

EPSS — Exploit Prediction

0.0003

Probability of exploitation

0.08%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-367 CWE-367

CWE-639 CWE-639

Affected Products

Vendor	Product	Versions
openproject	openproject	< 17.3.0

References

Advisories & Patches

https://github.com/opf/openproject/commit/8f693a1f35d0a84bb69af78fb6925f74329ae4fe https://github.com/opf/openproject/security/advisories/GHSA-hh5p-gwf8-h245 https://github.com/opf/openproject/security/advisories/GHSA-hh5p-gwf8-h245

Exploits

https://github.com/opf/openproject/security/advisories/GHSA-hh5p-gwf8-h245 https://github.com/opf/openproject/security/advisories/GHSA-hh5p-gwf8-h245

Frequently Asked Questions

What is CVE-2026-40896? +

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. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-40896? +

CVE-2026-40896 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0003, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-40896? +

CVE-2026-40896 affects products from openproject, specifically: openproject. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-40896? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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