{"cve":"CVE-2026-8034","nvd":{"published":"2026-05-07T22:16:37.230","modified":"2026-10-26T20:10:00.160","status":"Analyzed","description":"A server-side request forgery (SSRF) vulnerability was identified in the GitHub Enterprise Server notebook viewer that allowed an attacker to access internal services by exploiting URL parser confusion between the validation layer and the HTTP request library. The hostname validation used a different URL parser than the request library, enabling a crafted URL to pass validation while directing the request to an unintended host. Exploitation required network access to the GitHub Enterprise Server instance. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.16.18, 3.17.15, 3.18.9, 3.19.6, and 3.20.2. This vulnerability was reported via the GitHub Bug Bounty program.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H","score":7.9},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-436","CWE-918"],"references":["https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.18","https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.15","https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.9","https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.6","https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.2"],"products":["github:enterprise_server"],"source":"nvd","synced_at":"2026-10-26T20:34:58.897451322+00:00"},"epss":{"cve":"CVE-2026-8034","score":0.0052,"percentile":0.43914,"date":"2026-10-26"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}