CVE-2026-44731 — OpenProject: Improper Access Control on OpenProject through /projects/[projectName]/meetings via "invited_user_id" in GET parameter "filters" leads to user name

OpenProject is open-source, web-based project management software. Prior to 17.3.2 and 17.4.0, the web application's meetings filter feature leaks whether a given user ID corresponds to a valid account and discloses the user's full name, allowing an attacker to enumerate all existing user accounts by probing user IDs and observing differences in the server response. This vulnerability is fixed in 17.3.2 and 17.4.0.

Published Jun 26, 2026Updated Jun 29, 2026Sources: cvelistV5, GitHub_M

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

chance of exploitation in 30 days

Affects

opf

openproject

CVSS base

4.3

MEDIUM

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script all four kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Affected scope

The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.

Vendors (1)

opf

Products (1)

openproject

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
4.3	CVSS 3.1	MEDIUM	—	—	cvelistV5

Weakness & attack patterns

CWE-639

References

1 on the record

github.com/opf/openproject/security/advisories/GHSA-x7j3-cfgf-7mc4
x_refsource_CONFIRM

Elsewhere on this site

opfevery CVE for this vendor
CWE-639other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.