CVE-2025-55735 flaskBlog Stored XSS Vulnerability
Attackers can inject malicious scripts into blog posts via unvalidated content, leading to stored XSS when rendered without escaping.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2025-55735?
CVE-2025-55735 is a medium-severity cross-site scripting vulnerability in DogukanUrker FlaskBlog, published on 19 Aug 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Which versions are affected by CVE-2025-55735?
It affects 1 product.
Products include Dogukanurker Flaskblog.
How do I fix CVE-2025-55735?
No fix has been published for CVE-2025-55735 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-2025-55735 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-55735 exists.
Other vulnerabilities in DogukanUrker FlaskBlog
Sources
Also known as GHSA-gj9v-qhc3-gcfx.