Security readout for executives and security teams
Plain-English summary
A logged-in OpenProject user could force other users to be logged out by deleting session records that were not properly ownership-checked. This does not expose other users’ session details or data, but it can disrupt access and productivity. Fixed versions are available.
Executive priority
Prioritize patching in the normal urgent maintenance cycle, especially for shared or externally accessible OpenProject systems. The business risk is disruption, not data theft, but repeated forced logouts could affect operations and user trust.
Technical view
OpenProject before 16.6.5 and version 17.0.0 allowed authenticated users to delete sessions through the user sessions feature without verifying that the target session belonged to them. Session object IDs were incremental, enabling unauthorized termination of other users’ sessions. CVSS is 6.5 with high availability impact and no confidentiality or integrity impact.
Likely exposure
Exposure is limited to OpenProject deployments running versions earlier than 16.6.5 or exactly 17.0.0, where an attacker already has a valid user account. Internet exposure increases disruption risk, but authentication is required.
Exploitation context
No public source in the provided bundle states active exploitation, and the CVE is not listed as KEV. The issue is low complexity for an authenticated user and mainly causes denial of service by logging users out.
Researcher notes
The root issue is missing authorization on session deletion, with predictable incremental session identifiers. The advisory states users could not view other users’ stored session metadata. Avoid assuming broader account compromise without separate evidence.
Mitigation direction
- Upgrade OpenProject 16.x deployments to 16.6.5 or later.
- Upgrade OpenProject 17.0.0 deployments to 17.0.1 or later.
- If upgrading is delayed, monitor vendor guidance; sources state no workaround is available.
- Review user account access and remove unnecessary accounts to reduce abuse opportunity.
Validation and detection
- Inventory all OpenProject instances and record installed versions.
- Confirm no instance is below 16.6.5 or exactly 17.0.0.
- Verify the upgrade completed using OpenProject release or package metadata.
- Review logs for unusual volume of user session deletion activity.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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CWE-488: Exact CWE lookup
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Open ATT&CK lookupCVE-2026-23646 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H2.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/opf/openproject/security/advisories/GHSA-w422-xf8f-v4vpCVE reference · x_refsource_CONFIRM
- https://github.com/opf/openproject/releases/tag/v16.6.5CVE reference · x_refsource_MISC
- https://github.com/opf/openproject/releases/tag/v17.0.1CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Exposure of Data Element to Wrong Session
Exposure of Data Element to Wrong Session represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.