CVE-2026-44696Public exploitNetwork attack vector

Phishing overlays via permissive inline-style sanitization

Published Jun 26, 2026 · Updated Jun 26, 2026

Stored CSS injection in OpenProject before 17.4.0 allows remote authenticated users to create phishing overlays in rich-text fields. The SanitizationFilter passes inline styles through Sanitize::Config::RELAXED[:css], retaining positioning and URL-bearing properties on allowed elements. The attacker needs write access to a formattable field, and a victim must view the stored content; the result is UI spoofing or an external metadata-bearing request, not script execution.

CVSS severity5.7
Medium
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored CSS injection in OpenProject before 17.4.0 allows remote authenticated users to create phishing overlays in rich-text fields. The SanitizationFilter passes inline styles through Sanitize::Config::RELAXED[:css], retaining positioning and URL-bearing properties on allowed elements. The attacker needs write access to a formattable field, and a victim must view the stored content; the result is UI spoofing or an external metadata-bearing request, not script execution.

The record

CVE
CVE-2026-44696
Published
Jun 26, 2026
Updated
Jun 26, 2026
Vendor
OpenProject GmbH
Product
OpenProject
Classifications
CWE-79
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=< 17.4.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenProject GmbH · OpenProjectversion=< 17.4.0

Published CVSS scores

5.7GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Public exploit references

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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