# 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.

- **Severity:** Medium 5.3 (`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`)
- **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 available:** No
- **Published:** 19 Aug 2025
- **Updated:** 19 Aug 2025
- **Also known as:** GHSA-gj9v-qhc3-gcfx

## 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.

Weakness: CWE-807 (Reliance on Untrusted Inputs in a Security Decision), CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2025-55735?

It affects 1 product.


Products: 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.

## 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

- [CVE-2025-55736](https://insights.sbomify.com/CVE-2025-55736/): flaskBlog allows arbitrary privilege escalation (critical 9.3)
- [CVE-2025-28104](https://insights.sbomify.com/CVE-2025-28104/): Missing authorization in n/a (critical 9.1)
- [CVE-2025-55734](https://insights.sbomify.com/CVE-2025-55734/): flaskBlo Authorization Bypass (medium 6.9)
- [CVE-2025-55737](https://insights.sbomify.com/CVE-2025-55737/): flaskBlog arbitrary comment delete (medium 6.9)
- [CVE-2025-28101](https://insights.sbomify.com/CVE-2025-28101/): Cross-site request forgery in n/a (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-55735 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-55735 exists.

Affected product: DogukanUrker FlaskBlog. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-55735/ (Markdown: https://insights.sbomify.com/CVE-2025-55735/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-55735
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-55735
- OSV: https://osv.dev/vulnerability/CVE-2025-55735

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-55735/
Summaries are generated and may contain mistakes; the official description above is the record.