What is the CVSS score of CVE-2026-29038?

CVE-2026-29038 has a CVSS 3.1 base score of 6.1 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N. EPSS exploitation probability: 0.0%.

Which versions of Flask are affected by CVE-2026-29038?

Organizations using changedetection.io should be aware of moderate risk from CVE-2026-29038, a cross-site scripting vulnerability rated CVSS 6.1.. A patch is available.

Is there a public PoC exploit available for CVE-2026-29038?

Yes, a public proof-of-concept exploit is available for CVE-2026-29038. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-29038?

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

Flask CVE-2026-29038

MEDIUM

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

2026-03-06 security-advisories@github.com

GHSA-8whx-v8qq-pq64

Flask XSS Changedetection

6.1

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

6.1 MEDIUM

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:06 vuln.today

PoC Detected

Mar 10, 2026 - 19:38 vuln.today

Public exploit code

Patch released

Mar 10, 2026 - 19:38 nvd

Patch available

CVE Published

Mar 06, 2026 - 07:16 nvd

MEDIUM 6.1

DescriptionGitHub Advisory

changedetection.io is a free open source web page change detection tool. Prior to version 0.54.4, there is a reflected cross-site scripting (XSS) vulnerability identified in the /rss/tag/ endpoint of changedetection.io. The tag_uuid path parameter is reflected directly in the HTTP response body without HTML escaping. Since Flask returns text/html by default for plain string responses, the browser parses and executes injected JavaScript. This issue has been patched in version 0.54.4.

AnalysisAI

Reflected XSS in changedetection.io versions prior to 0.54.4 allows unauthenticated remote attackers to inject malicious JavaScript through the /rss/tag/ endpoint via an unescaped tag_uuid parameter, enabling session hijacking or credential theft when victims visit crafted links. The vulnerability requires user interaction to trigger and affects the Flask-based application with public exploit code available. Users should upgrade to version 0.54.4 or later immediately.

Technical ContextAI

Classified as CWE-79 (Cross-site Scripting (XSS)). Affects Changedetection. changedetection.io is a free open source web page change detection tool. Prior to version 0.54.4, there is a reflected cross-site scripting (XSS) vulnerability identified in the /rss/tag/ endpoint of changedetection.io. The tag_uuid path parameter is reflected directly in the HTTP response body without HTML escaping. Since Flask returns text/html by default for plain string responses, the browser parses and executes injected JavaScript. This issue has been patched in version 0.54.4.

RemediationAI

A vendor patch is available — apply it immediately. Fixed in version 0.54.4.. Implement output encoding and Content Security Policy headers. Restrict network access to the affected service where possible.