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TI-2025-34958 Aliases CVE-2025-55303GHSA-xf8x-j4p2-f749

Unauthorized third-party images in Astro’s _image endpoint

Priority HIGH 70CWE-115Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Cross-site scripting
Confidentiality · integrity · availability
None · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-79.

Summary

Astro is a web framework for content-driven websites. In versions of astro before 5.13.2 and 4.16.18, the image optimization endpoint in projects deployed with on-demand rendering allows images from unauthorized third-party domains to be served. On-demand rendered sites built with Astro include an /_image endpoint which returns optimized versions of images. A bug in impacted versions of astro allows an attacker to bypass the third-party domain restrictions by using a protocol-relative URL as the image source, e.g. /_image?href=//example.com/image.png. This vulnerability is fixed in 5.13.2 and 4.16.18.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00637 50th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed astro (withastro): 5.13.2, 4.16.18astro (npm): 5.13.2, 4.16.19+1 more product

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
withastroastro5.0.0-alpha.0 to before 5.13.2; before 4.16.185.13.2, 4.16.18Patch availableCNA
—astro (npm)5.0.0-alpha.0 to before 5.13.25.13.2Patch availableGHSA-xf8x-j4p2-f749
—@astrojs/node (npm)before 9.1.19.1.1Patch availableGHSA-xf8x-j4p2-f749
—astro (npm)before 4.16.194.16.19Patch availableGHSA-xf8x-j4p2-f749
  • astro Vendorwithastro Affected 5.0.0-alpha.0 to before 5.13.2; before 4.16.18 Fixed in 5.13.2, 4.16.18 Patch available CNA
  • astro (npm) Vendor— Affected 5.0.0-alpha.0 to before 5.13.2 Fixed in 5.13.2 Patch available GHSA-xf8x-j4p2-f749
  • @astrojs/node (npm) Vendor— Affected before 9.1.1 Fixed in 9.1.1 Patch available GHSA-xf8x-j4p2-f749
  • astro (npm) Vendor— Affected before 4.16.19 Fixed in 4.16.19 Patch available GHSA-xf8x-j4p2-f749

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:astro:astro:*:*:*:*:*:node.js:*:*before 4.16.18; 5.0.0 to before 5.13.2Vulnerablewithastro
  • cpe:2.3:a:astro:astro:*:*:*:*:*:node.js:*:* Versions before 4.16.18; 5.0.0 to before 5.13.2 Vulnerable ·withastro

Remediation

  • Fix · CNA astro (withastro) Fixed in 5.13.2, 4.16.18
  • Fix · GHSA-xf8x-j4p2-f749 astro (npm) Fixed in 5.13.2 Advisory →
  • Fix · GHSA-xf8x-j4p2-f749 @astrojs/node (npm) Fixed in 9.1.1 Advisory →
  • Fix · GHSA-xf8x-j4p2-f749 astro (npm) Fixed in 4.16.19 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-55303
  2. 2026-10-03 Alias added: GHSA-xf8x-j4p2-f749
  3. 2026-10-25 EPSS moved to the 50th–90th percentile

References

Exploit 1

Patch 1

Advisory 1

Other 1

  • TI-2024-37142 Server source code is exposed to the public if sourcemaps are enabled CVSS 4.0HIGH 7.8
  • TI-2025-39915 Server-side request forgery in withastro astro CVSS 3.1MEDIUM 6.5
  • TI-2025-38274 Astro's `X-Forwarded-Host` is reflected with no validation CVSS 3.1MEDIUM 6.5
  • TI-2026-36915 Astro: Reflected XSS via unescaped slot name CVSS 3.1HIGH 7.1
  • TI-2025-40102 Astro is vulnerable to Reflected XSS via the server islands feature CVSS 3.1HIGH 7.1
  • TI-2025-34548 Astro: Duplicate trailing slash feature can lead to Open Redirects CVSS 4.0MEDIUM 5.5
See all 19 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences