CVE-2026-40896Public exploitNetwork attack vector

Cross-project agenda injection via unscoped section lookup

Published Apr 20, 2026 · Updated Apr 20, 2026

Authorization bypass in OpenProject before 17.3.0 allows remote authenticated users to inject agenda items into inaccessible projects. The move_to_section action resolves a user-supplied section ID globally, authorizes the item against its original project, then a before-save callback reassigns its meeting. Any user with manage_agendas in one project can enumerate sequential section IDs and plant write-only content in every meeting, but cannot read target meetings.

CVSS severity6.5
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in OpenProject before 17.3.0 allows remote authenticated users to inject agenda items into inaccessible projects. The move_to_section action resolves a user-supplied section ID globally, authorizes the item against its original project, then a before-save callback reassigns its meeting. Any user with manage_agendas in one project can enumerate sequential section IDs and plant write-only content in every meeting, but cannot read target meetings.

The record

CVE
CVE-2026-40896
Published
Apr 20, 2026
Updated
Apr 20, 2026
Vendor
OpenProject GmbH
Product
OpenProject
Classifications
CWE-639, CWE-367, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 17.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenProject GmbH · OpenProjectversion=< 17.3.0

Published CVSS scores

6.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
7.1NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key
CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
T1565.001Stored Data Manipulation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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