CVE-2026-52781Network attack vector

Stored browser redirection via wildcard macro data attributes

Published Jun 26, 2026 · Updated Jun 26, 2026

Stored cross-site scripting in OpenProject before 17.3.3 and version 17.4.0 allows remote authenticated users to redirect victim browsers. The sanitizer permits any data-* attribute on macro elements, so a crafted description mounts the poll-for-changes Stimulus controller, fetches an uploaded attachment, and passes it to renderStreamMessage() as Turbo Stream actions. An account able to edit a work package and upload an attachment can invoke redirect_to in authenticated viewers' sessions; no server-side code execution is reported.

CVSS severity6.4
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored cross-site scripting in OpenProject before 17.3.3 and version 17.4.0 allows remote authenticated users to redirect victim browsers. The sanitizer permits any data-* attribute on macro elements, so a crafted description mounts the poll-for-changes Stimulus controller, fetches an uploaded attachment, and passes it to renderStreamMessage() as Turbo Stream actions. An account able to edit a work package and upload an attachment can invoke redirect_to in authenticated viewers' sessions; no server-side code execution is reported.

The record

CVE
CVE-2026-52781
Published
Jun 26, 2026
Updated
Jun 26, 2026
Vendor
OpenProject GmbH
Product
OpenProject
Classifications
Unavailable
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 26, 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=< 17.3.3
  2. Affected versionversion=>= 17.4.0, < 17.4.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenProject GmbH · OpenProjectversion=< 17.3.3; version=>= 17.4.0, < 17.4.1

Published CVSS scores

6.4OpenProjectCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/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 exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

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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