What’s Vulnerable › Vulnerabilities

CVE-2024-4023: Stored XSS in flatpressblog/flatpress

• Severity: high (CVSS 8.1 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.8% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2025-03-20 · updated 2026-06-17
• Weakness: CWE-79

Description

A stored cross-site scripting (XSS) vulnerability exists in flatpressblog/flatpress version 1.3. When a user uploads a file with a `.xsig` extension and directly accesses this file, the server responds with a Content-type of application/octet-stream, leading to the file being processed as an HTML file. This allows an attacker to execute arbitrary JavaScript code, which can be used to steal user cookies, perform HTTP requests, and access content of the same origin.

Affected products

• flatpressblog/flatpress: 1.3

References

• https://github.com/flatpressblog/flatpress/commit/3c9cc69364a45fd3f92d4bd606344b5dd1205d6a
• https://huntr.com/bounties/ed803c13-0858-4c22-93ba-bf2384ab1e9d

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