Which versions of Halo are affected by CVE-2024-56156?

Organizations using Halo should be aware of moderate risk from CVE-2024-56156, a cross-site scripting vulnerability rated CVSS 5.5.

Is there a public PoC exploit available for CVE-2024-56156?

Yes, a public proof-of-concept exploit is available for CVE-2024-56156. Prioritise patching immediately. EPSS: 1.0%.

How to fix or mitigate CVE-2024-56156?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Verify Content-Security-Policy and output encoding.

Halo CVE-2024-56156

Q: What is the CVSS score of CVE-2024-56156?

CVE-2024-56156 has a CVSS 4.0 base score of 5.5 (Medium). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:L/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 1.0%.

MEDIUM

Cross-site Scripting (XSS) (CWE-79)

2025-04-25 security-advisories@github.com

XSS RCE Halo

5.5

CVSS 4.0 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

5.5 MEDIUM

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:L/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

Analysis Generated

Mar 28, 2026 - 18:38 vuln.today

PoC Detected

Feb 03, 2026 - 19:16 vuln.today

Public exploit code

CVE Published

Apr 25, 2025 - 16:15 nvd

MEDIUM 5.5

DescriptionGitHub Advisory

Halo is an open source website building tool. Prior to version 2.20.13, a vulnerability in Halo allows attackers to bypass file type validation controls. This bypass enables the upload of malicious files including executables and HTML files, which can lead to stored cross-site scripting attacks and potential remote code execution under certain circumstances. This issue has been patched in version 2.20.13.

AnalysisAI

Halo is an open source website building tool. Rated medium severity (CVSS 5.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified as Cross-Site Scripting (XSS) (CWE-79), which allows attackers to inject malicious scripts into web pages viewed by other users. Halo is an open source website building tool. Prior to version 2.20.13, a vulnerability in Halo allows attackers to bypass file type validation controls. This bypass enables the upload of malicious files including executables and HTML files, which can lead to stored cross-site scripting attacks and potential remote code execution under certain circumstances. This issue has been patched in version 2.20.13. Affected products include: Halo. Version information: version 2.20.13.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Sanitize all user input, use Content-Security-Policy headers, encode output contextually (HTML, JS, URL). Use frameworks with built-in XSS protection.