Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.24% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-23625High confidence
OpenProject has stored XSS regression using attachments and script-src self
opf · openproject
Official source article: GitHub GHSA-CVPQ-CC56-GWXX ↗. Check the applicable product and release in the original source.
8.7HighCVSS 3.1
Within 7 days
Mitigation availableHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
Compensating controls
- Apply the linked authoritative mitigation while planning the permanent fix.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs opf openproject and falls inside the recorded affected range.
- Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Mitigation available01
What, why and how
OpenProject is an open-source, web-based project management software. Versions 16.3.0 through 16.6.4 are affected by a stored cross-site scripting vulnerability in the Roadmap view. OpenProject’s roadmap view renders the “Related work packages” list for each version. When a version contains work packages from a different project (e.g., a subproject), the helper link_to_work_package prepends package.project.to_s to the link and returns the entire string with .html_safe. Because project names are user-controlled and no escaping happens before calling html_safe, any HTML placed in a subproject name is injected verbatim into the page. The underlying issue is mitigated in versions 16.6.5 and 17.0.0 by setting a `X-Content-Type-Options: nosniff` header, which was in place until a refactoring move to Rails standard content-security policy, which did not properly apply this header in the new configuration since OpenProject 16.3.0. Those who cannot upgrade their installations should ensure that they add a X-Content-Type-Options: nosniff header in their proxying web application server.
What
OpenProject is an open-source, web-based project management software. Versions 16.3.0 through 16.6.4 are affected by a stored cross-site scripting vulnerability in the Roadmap view. OpenProject’s roadmap view renders the “Related work packages” list for each version. When a version contains work packages from a different project (e.g., a subproject), the helper link_to_work_package prepends package.project.to_s to the link and returns the entire string with .html_safe. Because project names are user-controlled and no escaping happens before calling html_safe, any HTML placed in a subproject name is injected verbatim into the page. The underlying issue is mitigated in versions 16.6.5 and 17.0.0 by setting a `X-Content-Type-Options: nosniff` header, which was in place until a refactoring move to Rails standard content-security policy, which did not properly apply this header in the new configuration since OpenProject 16.3.0. Those who cannot upgrade their installations should ensure that they add a X-Content-Type-Options: nosniff header in their proxying web application server.
Why
Attacker-controlled content can reach a browser as executable script without sufficient output encoding or sanitisation.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
OpenProject is an open-source, web-based project management software. Versions 16.3.0 through 16.6.4 are affected by a stored cross-site scripting vulnerability in the Roadmap view. OpenProject’s roadmap view renders the “Related work packages” list for each version. When a version contains work packages from a different project (e.g., a subproject), the helper link_to_work_package prepends package.project.to_s to the link and returns the entire string with .html_safe. Because project names are user-controlled and no escaping happens before calling html_safe, any HTML placed in a subproject name is injected verbatim into the page. The underlying issue is mitigated in versions 16.6.5 and 17.0.0 by setting a `X-Content-Type-Options: nosniff` header, which was in place until a refactoring move to Rails standard content-security policy, which did not properly apply this header in the new configuration since OpenProject 16.3.0. Those who cannot upgrade their installations should ensure that they add a X-Content-Type-Options: nosniff header in their proxying web application server.
Why
Attacker-controlled content can reach a browser as executable script without sufficient output encoding or sanitisation.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- Required interaction required
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Changed: exploitation can affect a different security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-79 ↗
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'). The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:NCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SChangedScope: The attack can affect a component governed by a different security authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.ANoneAvailability impact: No direct loss is represented by this metric.- Post-exploitation / living off the land
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Mitigation available
- Affected
- openproject: >= 16.3.0, < 16.6.5
- Action
- Apply the mitigation in the linked authoritative guidance while planning the vendor's permanent fix.
- Workaround
- A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04
Evidence and provenance
Published 19 Jan 2026 · Last source change 20 Jan 2026, 15:10 UTC · CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-3309
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
CVE published
Mitigation reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.