What is CVE-2025-53528?

CVE-2025-53528 is a high-severity vulnerability in Zmievsa Cadwyn, classified under Cross-site Scripting. CVSS score: 7.6/10. Published 2025-07-21.

How severe is CVE-2025-53528?

High severity. CVSS v3 base score is 7.6 out of 10.

XSS in Zmievsa Cadwyn

CVE-2025-53528

Cadwyn creates production-ready community-driven modern Stripe-like API versioning in FastAPI. In versions before 5.4.3, the version parameter of the "/docs" endpoint is vulnerable to a Reflected XSS (Cross-Site Scripting) attack. This XSS would notably allow an attacker to execute JavaScript code on a user's session for any application based on Cadwyn via a one-click attack. The vulnerability has been fixed in version 5.4.3.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (15.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:L.

Affected products

Zmievsa Cadwyn — versions < 5.4.3

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

security-advisories@github.com (x_refsource_CONFIRM)
security-advisories@github.com (x_refsource_MISC)

Frequently asked questions

What is CVE-2025-53528?: CVE-2025-53528 is a high-severity vulnerability in Zmievsa Cadwyn, classified under Cross-site Scripting. CVSS score: 7.6/10. Published 2025-07-21.
How severe is CVE-2025-53528?: High severity. CVSS v3 base score is 7.6 out of 10.