What is the CVSS score of CVE-2026-21431?

CVE-2026-21431 has a CVSS 3.1 base score of 5.4 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N. EPSS exploitation probability: 0.0%.

Which versions of Emlog are affected by CVE-2026-21431?

Organizations using Emlog should be aware of moderate risk from CVE-2026-21431, a cross-site scripting vulnerability rated CVSS 5.4.

Is there a public PoC exploit available for CVE-2026-21431?

Yes, a public proof-of-concept exploit is available for CVE-2026-21431. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-21431?

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

Emlog CVE-2026-21431

MEDIUM

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

2026-01-02 security-advisories@github.com

XSS Emlog

5.4

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

5.4 MEDIUM

AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

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

CVSS VectorGitHub Advisory

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:54 vuln.today

PoC Detected

Jan 16, 2026 - 17:13 vuln.today

Public exploit code

CVE Published

Jan 02, 2026 - 19:15 nvd

MEDIUM 5.4

DescriptionGitHub Advisory

Emlog is an open source website building system. Version 2.5.23 has a stored cross-site scripting vulnerability in the Resource media library function while publishing an article. As of time of publication, no known patched versions are available.

AnalysisAI

Stored XSS in Emlog 2.5.23's media library function allows authenticated attackers to inject malicious scripts when publishing articles, which execute in other users' browsers with scope crossing enabled. Public exploit code exists for this vulnerability, and no patched version is currently available. Successful exploitation requires user interaction and grants attackers the ability to steal session data or perform actions on behalf of affected users.

Technical ContextAI

Classified as CWE-79 (Cross-site Scripting (XSS)). Affects Emlog. Emlog is an open source website building system. Version 2.5.23 has a stored cross-site scripting vulnerability in the Resource media library function while publishing an article. As of time of publication, no known patched versions are available.

RemediationAI

Monitor vendor advisories for a patch. Implement output encoding and Content Security Policy headers. Restrict network access to the affected service where possible.