CVE-2026-41321 @astrojs/cloudflare: SSRF via redirect following in Cloudflare image-binding-transform endpoint
Attackers can bypass domain allowlists to force the server to fetch arbitrary URLs via redirect following, potentially accessing internal resources.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-41321?
CVE-2026-41321 is a low-severity server-side request forgery vulnerability in withastro @astrojs/cloudflare, published on 24 Apr 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
@astrojs/cloudflare is an SSR adapter for use with Cloudflare Workers targets. Prior to 13.1.10, the fetch() call for remote images in packages/integrations/cloudflare/src/utils/image-binding-transform.ts uses the default redirect: 'follow' behavior. This allows the Cloudflare Worker to follow HTTP redirects to arbitrary URLs, bypassing the isRemoteAllowed() domain allowlist check which only validates the initial URL. This vulnerabiity is caused by an incomplete fix for CVE-2025-58179. This vulnerability is fixed in 13.1.10.
Weakness: CWE-918
Which versions are affected by CVE-2026-41321?
2 open source packages ship an affected version, including @astrojs/cloudflare.
| Package | Affected | Fixed in |
|---|---|---|
@astrojs/cloudflare npm | All versions | 13.1.10 |
@astrojs/cloudflare npm | All versions | 13.1.10 |
How do I fix CVE-2026-41321?
Upgrade @astrojs/cloudflare to 13.1.10 or later.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-41321 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41321 exists.
Sources
Also known as GHSA-88gm-j2wx-58h6.