CVE-2026-22604Network attack vector

Unauthenticated username enumeration via password-change error

Published Jan 10, 2026 · Updated Jan 10, 2026

Information disclosure in OpenProject 11.2.1 through 16.6.1 allows remote attackers to enumerate usernames via password-change requests. The unauthenticated /account/change_password handler accepts an arbitrary password_change_user_id and renders the matched account's username on its error page. No account or user interaction is required; the response reveals registered usernames but provides no reported data modification or service interruption.

CVSS severity6.9
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in OpenProject 11.2.1 through 16.6.1 allows remote attackers to enumerate usernames via password-change requests. The unauthenticated /account/change_password handler accepts an arbitrary password_change_user_id and renders the matched account's username on its error page. No account or user interaction is required; the response reveals registered usernames but provides no reported data modification or service interruption.

The record

CVE
CVE-2026-22604
Published
Jan 10, 2026
Updated
Jan 10, 2026
Vendor
OpenProject GmbH
Product
OpenProject
Classifications
CWE-200, T1087
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=>= 11.2.1, < 16.6.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenProject GmbH · OpenProjectversion=>= 11.2.1, < 16.6.2

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
6.9GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA: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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1087Account Discovery

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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