{"api_version":"1","generated_at":"2026-05-08T10:58:05+00:00","cve":"CVE-2026-8034","urls":{"html":"https://cve.report/CVE-2026-8034","api":"https://cve.report/api/cve/CVE-2026-8034.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-8034","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-8034"},"summary":{"title":"Server-side request forgery vulnerability in GitHub Enterprise Server notebook viewer via URL parser confusion","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.","state":"PUBLISHED","assigner":"GitHub_P","published_at":"2026-05-07 22:16:37","updated_at":"2026-05-07 22:16:37"},"problem_types":["CWE-436","CWE-918","CWE-918 CWE-918 Server-Side request forgery (SSRF)","CWE-436 CWE-436 Interpretation Conflict"],"metrics":[{"version":"4.0","source":"product-cna@github.com","type":"Secondary","score":"7.9","severity":"HIGH","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","data":{"version":"4.0","vectorString":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","baseScore":7.9,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"HIGH","subIntegrityImpact":"HIGH","subAvailabilityImpact":"HIGH","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}},{"version":"4.0","source":"CNA","type":"CVSS","score":"7.9","severity":"HIGH","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","data":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":7.9,"baseSeverity":"HIGH","exploitMaturity":"NOT_DEFINED","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"HIGH","subConfidentialityImpact":"HIGH","subIntegrityImpact":"HIGH","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"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","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"}}],"references":[{"url":"https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.18","name":"https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.18","refsource":"product-cna@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.2","name":"https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.2","refsource":"product-cna@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.15","name":"https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.15","refsource":"product-cna@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.6","name":"https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.6","refsource":"product-cna@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.9","name":"https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.9","refsource":"product-cna@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-8034","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-8034","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"GitHub","product":"Enterprise Server","version":"affected 3.16.0 3.16.17 semver","platforms":[]},{"source":"CNA","vendor":"GitHub","product":"Enterprise Server","version":"affected 3.17.0 3.17.14 semver","platforms":[]},{"source":"CNA","vendor":"GitHub","product":"Enterprise Server","version":"affected 3.18.0 3.18.8 semver","platforms":[]},{"source":"CNA","vendor":"GitHub","product":"Enterprise Server","version":"affected 3.19.0 3.19.5 semver","platforms":[]},{"source":"CNA","vendor":"GitHub","product":"Enterprise Server","version":"affected 3.20.0 3.20.1 semver","platforms":[]},{"source":"CNA","vendor":"GitHub","product":"Enterprise Server","version":"unaffected 3.21.0 semver","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[{"source":"CNA","value":"R31n","lang":"en"}],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"affected","product":"Enterprise Server","vendor":"GitHub","versions":[{"changes":[{"at":"3.16.18","status":"unaffected"}],"lessThanOrEqual":"3.16.17","status":"affected","version":"3.16.0","versionType":"semver"},{"changes":[{"at":"3.17.15","status":"unaffected"}],"lessThanOrEqual":"3.17.14","status":"affected","version":"3.17.0","versionType":"semver"},{"changes":[{"at":"3.18.9","status":"unaffected"}],"lessThanOrEqual":"3.18.8","status":"affected","version":"3.18.0","versionType":"semver"},{"changes":[{"at":"3.19.6","status":"unaffected"}],"lessThanOrEqual":"3.19.5","status":"affected","version":"3.19.0","versionType":"semver"},{"changes":[{"at":"3.20.2","status":"unaffected"}],"lessThanOrEqual":"3.20.1","status":"affected","version":"3.20.0","versionType":"semver"},{"status":"unaffected","version":"3.21.0","versionType":"semver"}]}],"credits":[{"lang":"en","type":"finder","value":"R31n"}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"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.<br><br>"}],"value":"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."}],"impacts":[{"capecId":"CAPEC-664","descriptions":[{"lang":"en","value":"CAPEC-664 Server Side Request Forgery"}]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":7.9,"baseSeverity":"HIGH","exploitMaturity":"NOT_DEFINED","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"HIGH","subConfidentialityImpact":"HIGH","subIntegrityImpact":"HIGH","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"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","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-918","description":"CWE-918 Server-Side request forgery (SSRF)","lang":"en","type":"CWE"},{"cweId":"CWE-436","description":"CWE-436 Interpretation Conflict","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-05-07T21:18:49.812Z","orgId":"82327ea3-741d-41e4-88f8-2cf9e791e760","shortName":"GitHub_P"},"references":[{"tags":["release-notes"],"url":"https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.18"},{"tags":["release-notes"],"url":"https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.15"},{"tags":["release-notes"],"url":"https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.9"},{"tags":["release-notes"],"url":"https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.6"},{"tags":["release-notes"],"url":"https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.2"}],"source":{"discovery":"EXTERNAL"},"title":"Server-side request forgery vulnerability in GitHub Enterprise Server notebook viewer via URL parser confusion","x_generator":{"engine":"Vulnogram 0.2.0"}}},"cveMetadata":{"assignerOrgId":"82327ea3-741d-41e4-88f8-2cf9e791e760","assignerShortName":"GitHub_P","cveId":"CVE-2026-8034","datePublished":"2026-05-07T21:18:49.812Z","dateReserved":"2026-05-06T13:06:48.690Z","dateUpdated":"2026-05-07T21:18:49.812Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-07 22:16:37","lastModifiedDate":"2026-05-07 22:16:37","problem_types":["CWE-436","CWE-918","CWE-918 CWE-918 Server-Side request forgery (SSRF)","CWE-436 CWE-436 Interpretation Conflict"],"metrics":{"cvssMetricV40":[{"source":"product-cna@github.com","type":"Secondary","cvssData":{"version":"4.0","vectorString":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","baseScore":7.9,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"HIGH","subIntegrityImpact":"HIGH","subAvailabilityImpact":"HIGH","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"8034","Ordinal":"1","Title":"Server-side request forgery vulnerability in GitHub Enterprise S","CVE":"CVE-2026-8034","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"8034","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"Server-side request forgery vulnerability in GitHub Enterprise S"}]}}}