CVE-2025-54793: Astro: Duplicate trailing slash feature can lead to Open Redirects

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2025-08-08 · updated 2026-06-17
Weakness: CWE-601

Description

Astro is a web framework for content-driven websites. In versions 5.2.0 through 5.12.7, there is an Open Redirect vulnerability in the trailing slash redirection logic when handling paths with double slashes. This allows an attacker to redirect users to arbitrary external domains by crafting URLs such as https://mydomain.com//malicious-site.com/. This increases the risk of phishing and other social engineering attacks. This affects sites that use on-demand rendering (SSR) with the Node or Cloudflare adapters. It does not affect static sites, or sites deployed to Netlify or Vercel. This issue is fixed in version 5.12.8. To work around this issue at the network level, block outgoing redirect responses with a Location header value that starts with `//`.

Affected products

withastro astro: from 5.2.0 before 5.12.7 — fixed in 5.12.7

How to fix

Upgrade to a fixed version: withastro astro 5.12.7. Check the vendor advisory for mitigations.

References

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