{"id":"CVE-2026-56100","summary":"SpringBlade 2.7.3 \u003c 5.0.0 Privilege Escalation via Exposed Feign Endpoint","details":"SpringBlade versions from 2.7.3 up to but not including 5.0.0 contain a privilege escalation vulnerability that allows authenticated attackers to create system administrator accounts by sending crafted POST requests to an unprotected internal Feign user-creation endpoint exposed via @RestController without authorization checks. Attackers can exploit the gateway's authentication filter, which only validates JWT parsing without verifying user roles or caller identity, and leverage a hardcoded JWT signing key embedded in publicly available JARs to forge tokens and escalate privileges from a low-privilege user to administrator, enabling cross-tenant data pollution and persistent backdoor access.","modified":"2026-08-31T03:45:12.095690039Z","published":"2026-08-28T18:00:36.953Z","database_specific":{"cna_assigner":"VulnCheck","cwe_ids":["CWE-862"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56100.json"},"references":[{"type":"WEB","url":"https://gitee.com/smallc/SpringBlade"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56100.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56100"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/springblade-privilege-escalation-via-exposed-feign-endpoint"},{"type":"FIX","url":"https://github.com/chillzhuang/SpringBlade/commit/c69b9547c942c697da2f3ee6a9265b6004abd645"},{"type":"PACKAGE","url":"https://github.com/chillzhuang/SpringBlade"},{"type":"PACKAGE","url":"https://github.com/chillzhuang/SpringBlade/releases#release-v5.0.0"},{"type":"EVIDENCE","url":"https://gist.github.com/sud0why/e73405057dd7414a8c221ef17e0d0059#file-cve-2026-56100-springblade-authbypass-en-md"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/chillzhuang/springblade","events":[{"introduced":"0"},{"fixed":"c69b9547c942c697da2f3ee6a9265b6004abd645"}],"database_specific":{"extracted_events":[{"introduced":"2.7.3"},{"fixed":"5.0.0"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v4.10.0","v4.9.0","v4.8.0","v4.7.0","v4.6.0","v4.5.0","v4.4.0","v4.3.0","v4.2.0","4.1.0","v4.0.0","v3.7.1","v3.7.0","v3.6.0","v3.5.0","v3.4.1","v3.4.0","v3.3.1","v3.3.0","v3.2.0","v3.1.0","v3.03","v3.0.2","v3.0.1","v3.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-56100.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"}]}