Astro is a web framework. Prior to version 10.0.0, Astro's Server Islands POST handler buffers and parses the full request body as JSON without enforcing a size limit. Because JSON.parse() allocates a V8 heap object for every element in the input, a crafted payload of many small JSON objects achieves ~15x memory amplification (wire bytes to heap bytes), allowing a single unauthenticated request to exhaust the process heap and crash the server. The /_server-islands/[name] route is registered on all Astro SSR apps regardless of whether any component uses server:defer, and the body is parsed before the island name is validated, so any Astro SSR app with the Node standalone adapter is affected. This issue has been patched in version 10.0.0.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-3rmj-9m5h-8fpv Astro: Memory exhaustion DoS due to missing request body size limit in Server Islands
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 24 Mar 2026 21:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 24 Mar 2026 19:00:00 +0000

Type Values Removed Values Added
Description Astro is a web framework. Prior to version 10.0.0, Astro's Server Islands POST handler buffers and parses the full request body as JSON without enforcing a size limit. Because JSON.parse() allocates a V8 heap object for every element in the input, a crafted payload of many small JSON objects achieves ~15x memory amplification (wire bytes to heap bytes), allowing a single unauthenticated request to exhaust the process heap and crash the server. The /_server-islands/[name] route is registered on all Astro SSR apps regardless of whether any component uses server:defer, and the body is parsed before the island name is validated, so any Astro SSR app with the Node standalone adapter is affected. This issue has been patched in version 10.0.0.
Title Astro: Memory exhaustion DoS due to missing request body size limit in Server Islands
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-03-24T20:17:11.483Z

Reserved: 2026-03-04T16:26:02.897Z

Link: CVE-2026-29772

cve-icon Vulnrichment

Updated: 2026-03-24T20:16:33.223Z

cve-icon NVD

Status : Received

Published: 2026-03-24T19:16:51.153

Modified: 2026-03-24T19:16:51.153

Link: CVE-2026-29772

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses