CVE-2025-53631 flaskBlog XSS Vulnerability in postContent

Medium 5.3 Published 14 Aug 2025 Updated 14 Aug 2025

Attackers can execute arbitrary JavaScript via unsanitized post content in flaskBlog, potentially compromising user sessions and data.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2025-53631?

CVE-2025-53631 is a medium-severity cross-site scripting vulnerability in DogukanUrker flaskBlog, published on 14 Aug 2025. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

flaskBlog is a blog app built with Flask. In versions 2.8.1 and prior, improper sanitization of postContent when submitting POST requests to /createpost leads to arbitrary JavaScript execution (XSS) on all pages the post is reflected on including /, /post/[ID], /admin/posts, and /user/[ID] of the user that made the post. At time of publication, there are no public patches available.

Weakness: CWE-79

Which versions are affected by CVE-2025-53631?

It affects 1 product.

Products include Dogukanurker Flaskblog.

How do I fix CVE-2025-53631?

No fix has been published for CVE-2025-53631 yet. Limit exposure of the affected software until one is available.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2025-53631 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-53631 exists.

Sources

Also known as GHSA-cj43-h8qf-7rw7.