# CVE-2025-53631: flaskBlog XSS Vulnerability in postContent

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

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Aug 2025
- **Updated:** 14 Aug 2025
- **Also known as:** GHSA-cj43-h8qf-7rw7

## 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 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2025-53631?

It affects 1 product.


Products: 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.

## Is CVE-2025-53631 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-53631 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-2025-53631 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-53631 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-2025-53631/ (Markdown: https://insights.sbomify.com/CVE-2025-53631/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-53631
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-53631
- OSV: https://osv.dev/vulnerability/CVE-2025-53631

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From sbomify Insights: https://insights.sbomify.com/CVE-2025-53631/
Summaries are generated and may contain mistakes; the official description above is the record.