What is the CVSS score of CVE-2026-21430?

CVE-2026-21430 has a CVSS 3.1 base score of 9.3 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N. EPSS exploitation probability: 0.0%.

Which versions of Emlog are affected by CVE-2026-21430?

Organizations using Emlog face critical risk from CVE-2026-21430, a cross-site scripting vulnerability rated CVSS 9.3.

Is there a public PoC exploit available for CVE-2026-21430?

Yes, a public proof-of-concept exploit is available for CVE-2026-21430. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-21430?

Within 24 hours: Identify all affected systems and apply vendor patches immediately. Verify anti-CSRF tokens and content security policies are enforced.

Emlog CVE-2026-21430

CRITICAL

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

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

XSS CSRF Emlog

9.3

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

9.3 CRITICAL

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

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

CVSS VectorGitHub Advisory

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:54 vuln.today

PoC Detected

Jan 16, 2026 - 19:07 vuln.today

Public exploit code

CVE Published

Jan 02, 2026 - 19:15 nvd

CRITICAL 9.3

DescriptionGitHub Advisory

Emlog is an open source website building system. In version 2.5.23, article creation functionality is vulnerable to cross-site request forgery (CSRF). This can lead to a user being forced to post an article with arbitrary, attacker-controlled content. This, when combined with stored cross-site scripting, leads to account takeover. As of time of publication, no known patched versions are available.

AnalysisAI

Emlog 2.5.23 is vulnerable to CSRF in article creation, which chains with stored XSS to achieve account takeover. An attacker can force an admin to create an article containing malicious JavaScript that steals their session. No patch available.

Technical ContextAI

The article creation endpoint lacks CSRF protection, allowing an attacker to forge requests that create articles with attacker-controlled content (CWE-79). By injecting JavaScript into the article body, the attacker achieves stored XSS that executes when any user (including admins) views the article, stealing session tokens or performing privileged actions.

RemediationAI

Implement CSRF tokens on all state-changing endpoints. Sanitize article content to prevent XSS. Consider migrating away from Emlog until patches are released.