What is the CVSS score of CVE-2026-27829?

CVE-2026-27829 has a CVSS 3.1 base score of 6.5 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L. EPSS exploitation probability: 0.0%.

Which versions of Astro are affected by CVE-2026-27829?

Organizations using versions 9.0.0 should be aware of notable risk from CVE-2026-27829, a server-side request forgery vulnerability rated CVSS 6.5.. A patch is available.

Is there a public PoC exploit available for CVE-2026-27829?

Yes, a public proof-of-concept exploit is available for CVE-2026-27829. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-27829?

Within 30 days: Identify affected systems running versions 9.0.0 and apply vendor patches as part of regular patch cycle. Vendor patch is available.

Astro CVE-2026-27829

MEDIUM

Server-Side Request Forgery (SSRF) (CWE-918)

2026-02-26 security-advisories@github.com

GHSA-cj9f-h6r6-4cx2

SSRF Astro Astrojs Node

6.5

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

6.5 MEDIUM

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

Low

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:55 vuln.today

PoC Detected

Mar 09, 2026 - 20:47 vuln.today

Public exploit code

Patch released

Mar 09, 2026 - 20:47 nvd

Patch available

CVE Published

Feb 26, 2026 - 01:16 nvd

MEDIUM 6.5

DescriptionGitHub Advisory

Astro is a web framework. In versions 9.0.0 through 9.5.3, a bug in Astro's image pipeline allows bypassing image.domains / image.remotePatterns restrictions, enabling the server to fetch content from unauthorized remote hosts. Astro provides an inferSize option that fetches remote images at render time to determine their dimensions. Remote image fetches are intended to be restricted to domains the site developer has manually authorized (using the image.domains or image.remotePatterns options). However, when inferSize is used, no domain validation is performed - the image is fetched from any host regardless of the configured restrictions. An attacker who can influence the image URL (e.g., via CMS content or user-supplied data) can cause the server to fetch from arbitrary hosts. This allows bypassing image.domains / image.remotePatterns restrictions to make server-side requests to unauthorized hosts. This includes the risk of server-side request forgery (SSRF) against internal network services and cloud metadata endpoints. Version 9.5.4 fixes the issue.

AnalysisAI

Astro web framework versions 9.0.0 through 9.5.3 fail to validate remote image domains when the inferSize option is enabled, allowing attackers to trigger server-side requests to arbitrary hosts and bypass configured image.domains and image.remotePatterns restrictions. An attacker controlling image URLs through CMS content or user input can exploit this to perform SSRF attacks or access unauthorized resources. Public exploit code exists for this vulnerability.

Technical ContextAI

Classified as CWE-918 (Server-Side Request Forgery (SSRF)). Affects \@Astrojs\/Node. Astro is a web framework. In versions 9.0.0 through 9.5.3, a bug in Astro's image pipeline allows bypassing image.domains / image.remotePatterns restrictions, enabling the server to fetch content from unauthorized remote hosts. Astro provides an inferSize option that fetches remote images at render time to determine their dimensions. Remote image fetches are intended to be restricted to domains the site developer has manually authorized (using the image.domains or image.remotePatterns