CVE-2025-55735

flaskBlog Stored XSS Vulnerability

Published Aug 19, 2025 CVSS 4.0 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
flaskBlog is a blog app built with Flask. In 2.8.0 and earlier, when creating a post, there's no validation of the content of the post stored in the variable "postContent". The vulnerability arises when displaying the content of the post using the | safe filter, that tells the engine to not escape the rendered content. This can lead to a stored XSS inside the content of the post. The code that causes the problem is in template/routes.html.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2025-25199 flaskBlog is a blog app built with Flask. In 2.8.0 and earlier, when creating a post, there's no validation of the content of the post stored in the variable "postContent". The vulnerability arises when displaying the content of the post using the | safe filter, that tells the engine to not escape the rendered content. This can lead to a stored XSS inside the content of the post. The code that causes the problem is in template/routes.html.
History
Type Values Removed Values Added
CPEs cpe:2.3:a:dogukanurker:flaskblog:*:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N'}

Type Values Removed Values Added
First Time appeared Dogukanurker
Dogukanurker flaskblog
Vendors & Products Dogukanurker
Dogukanurker flaskblog
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description flaskBlog is a blog app built with Flask. In 2.8.0 and earlier, when creating a post, there's no validation of the content of the post stored in the variable "postContent". The vulnerability arises when displaying the content of the post using the | safe filter, that tells the engine to not escape the rendered content. This can lead to a stored XSS inside the content of the post. The code that causes the problem is in template/routes.html.
Title flaskBlog Stored XSS Vulnerability
Weaknesses CWE-79
CWE-807
References
Metrics cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Aug 19, 2025, 7:18 PM
Reserved
Aug 14, 2025, 10:31 PM
Status
Analyzed
Published
Aug 19, 2025, 7:15 PM
Modified
Jun 17, 2026, 9:42 AM