CVE-2026-23646 | OpenProject users can delete other user's session, causing them to be logged out

OpenProject is an open-source, web-based project management software. Users of OpenProject versions prior to 16.6.5 and 17.0.1 have the ability to view and end their active sessions via Account Settings → Sessions. When deleting a session, it was not properly checked if the session belongs to the user. As the ID that is used to identify these session objects use incremental integers, users could iterate requests using `DELETE /my/sessions/:id` and thus unauthenticate other users. Users did not have access to any sensitive information (like browser identifier, IP addresses, etc) of other users that are stored in the session. The problem was patched in OpenProject versions 16.6.5 and 17.0.1. No known workarounds are available as this does not require any permissions or other that can temporarily be disabled.

Published: 2026-01-19 Last update: 2026-02-02 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-23646 is rated Low Risk (32.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.06%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-23646

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-21 0.03% 0.06% +0.03%
2 2026-01-20 — 0.03% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-23646

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 3.6 [email protected]

Weakness enumeration for CVE-2026-23646

Affected software / configurations for CVE-2026-23646

Vendor Product Version Raw CPE
openproject openproject < 16.6.5 cpe:2.3:a:openproject:openproject:*:*:*:*:*:*:*:*
openproject openproject 17.0.0 cpe:2.3:a:openproject:openproject:17.0.0:*:*:*:*:*:*:*

References for CVE-2026-23646

cvelogic Threat Intelligence