{"cve":"CVE-2026-57209","nvd":{"published":"2026-10-23T13:17:11.687","modified":"2026-10-23T19:57:42.660","status":"Deferred","description":"Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.17, when Heimdall operates in proxy mode, it constructs the Forwarded HTTP header after executing the matched rule pipeline by inserting the incoming request's Host header value directly into the header string without sanitizing commas or semicolons. This allows an attacker to inject additional parameters into the Forwarded header, potentially spoofing IP addresses for upstream services. This issue has been patched in version 0.17.17.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","score":7.0},"cvss_v3":null,"cwes":["CWE-20","CWE-74"],"references":["https://github.com/dadrus/heimdall/releases/tag/v0.17.17","https://github.com/dadrus/heimdall/security/advisories/GHSA-4jgr-pg2m-m988"],"products":[],"source":"nvd","synced_at":"2026-10-24T16:53:35.584907681+00:00"},"epss":{"cve":"CVE-2026-57209","score":0.00336,"percentile":0.26711,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-4jgr-pg2m-m988","url":"https://osv.dev/vulnerability/GHSA-4jgr-pg2m-m988","summary":"Heimdall: Forwarded Header Injection via Unsanitized Host Header in Proxy Mode","modified":"2026-07-20T21:56:16.566999339Z","packages":[{"ecosystem":"Go","name":"github.com/dadrus/heimdall","purl":"pkg:golang/github.com/dadrus/heimdall","ranges":["<0.17.17"],"fixed":["0.17.17"]}]},{"id":"GO-2026-5125","url":"https://osv.dev/vulnerability/GO-2026-5125","summary":"Heimdall: Forwarded Header Injection via Unsanitized Host Header in Proxy Mode in github.com/dadrus/heimdall","modified":"2026-07-20T21:56:16.566999339Z","packages":[{"ecosystem":"Go","name":"github.com/dadrus/heimdall","purl":"pkg:golang/github.com/dadrus/heimdall","ranges":["<0.17.17"],"fixed":["0.17.17"]}]}],"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."]}