🛡️ CVE-2025-55735 — flaskblog

🟡 CVSS 5.4 — Medium ⚠️ Exploit Public CWE-79 NVD
5.4
CVSS Score
0 Low4 Medium7 High9 Critical10

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.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. A user must be tricked into taking some action. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality low, integrity low, availability none.

Weakness class

CVE-2025-55735 is classified as CWE-79: Cross-site Scripting (XSS). User-supplied data is written into a page without escaping, so attacker script runs in the browser of anyone who views it.

Affected software

CVE-2025-55735 is recorded against 1 package.

  • flaskblog (fixed in 2.8.0)

Timeline and source

Published on 19 August 2025 and last revised on 17 June 2026. A public exploit is known to exist, which raises the urgency of patching considerably. Record sourced from NVD.

References

github.com

Details

Severity MEDIUM
CVSS Score 5.4
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
CWE CWE-79
Public Exploit ⚠️ Yes
Source NVD
Published 2025-08-19
Updated 2026-08-11
Modified 2026-06-17
Fix URL N/A

Affected Packages

Software From version Fixed in
flaskblog — 2.8.0

Similar Threats

Exploit Protection

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