{"id":"CVE-2026-103620","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-103620","generatedAt":"2026-10-28T01:00:58.040Z","title":"A missing authorization vulnerability was identified in GitHub Enterprise Server that allowed a repository collaborator with write access to delete the current default branch through the GraphQL API and cause an attacker-controlled branch to become the…","description":"A missing authorization vulnerability was identified in GitHub Enterprise Server that allowed a repository collaborator with write access to delete the current default branch through the GraphQL API and cause an attacker-controlled branch to become the new default. In repositories that required pull-request review but did not restrict branch deletion, this bypassed the review requirement and caused fresh clones and default-branch API requests to use attacker-controlled content. This vulnerability affected supported GitHub Enterprise Server releases in the 3.18, 3.19, 3.20, 3.21, and 3.22 series and was fixed in versions 3.18.16, 3.19.13, 3.20.9, 3.21.7, and 3.22.2. This vulnerability was reported via the GitHub Bug Bounty program.","published":"2026-10-06T19:17:40.000Z","lastModified":"2026-10-20T19:33:53.000Z","status":"Analyzed","sourceIdentifier":"product-cna@github.com","cvss":{"version":"4.0","score":6,"severity":"MEDIUM","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-862"],"affected":["github/enterprise server"],"epss":{"score":0.00499,"percentile":0.42518,"date":"2026-10-26","history":[{"date":"2026-10-07","score":0.00449,"percentile":0.36989}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.50%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-06T19:17:40.000Z","detail":{"score":"6.0","severity":"MEDIUM","publishedAt":"2026-10-06T19:17:39.700Z"},"summary":"New CVE, medium severity (CVSS 6.0)."}],"references":[{"url":"https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.16","tags":["Release Notes","Vendor Advisory"],"source":"product-cna@github.com"},{"url":"https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.13","tags":["Release Notes","Vendor Advisory"],"source":"product-cna@github.com"},{"url":"https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.9","tags":["Release Notes","Vendor Advisory"],"source":"product-cna@github.com"},{"url":"https://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.7","tags":["Release Notes","Vendor Advisory"],"source":"product-cna@github.com"},{"url":"https://docs.github.com/en/enterprise-server@3.22/admin/release-notes#3.22.2","tags":["Release Notes","Vendor Advisory"],"source":"product-cna@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-103620","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}