PT-2026-27479 · Astro · Astro

Adrgs

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Published

2026-03-24

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Updated

2026-03-25

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CVE-2026-29772

CVSS v3.1

7.5

High

VectorAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Name of the Vulnerable Software and Affected Versions Astro versions prior to 10.0.0
Description Astro's Server Islands POST handler does not enforce a size limit when buffering and parsing JSON request bodies. The JSON.parse() function allocates a V8 heap object for each element in the input, leading to approximately 15 times memory amplification. A crafted payload containing numerous small JSON objects can exhaust the process heap, causing the server to crash. The vulnerable code path is located in the / server-islands/[name] route, which is automatically registered for all Astro SSR applications using the Node standalone adapter, regardless of whether server-side rendering with defer is utilized. The request body is parsed before the island name is validated, meaning any value can be used in the [name] parameter. No authentication is required to exploit this issue.
Recommendations Update to Astro version 10.0.0 or later.

Exploit

Fix

DoS

Allocation of Resources Without Limits

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Weakness Enumeration

Related Identifiers

CVE-2026-29772
GHSA-3RMJ-9M5H-8FPV

Affected Products

Astro