{"id":"CVE-2026-59157","sourceIdentifier":"security-advisories@github.com","published":"2026-09-15T16:17:16.957","lastModified":"2026-09-30T17:51:56.193","vulnStatus":"Deferred","cveTags":[],"descriptions":[{"lang":"en","value":"webhookd is a minimalist webhook server that triggers shell scripts and external processes through HTTP requests. Prior to 1.22.0, webhookd deployments without htpasswd authentication forwarded all incoming HTTP headers through HTTPParamsToShellVars in pkg/api/index.go into the hook script environment without an allowlist. When an upstream reverse proxy did not strip a client-supplied X-WebAuthn-User header and a hook script trusted that variable for identity or privilege, a remote unauthenticated attacker could spoof another user, bypass script security controls, and access or modify resources available to the impersonated identity. This issue is fixed in version 1.22.0."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"ncarlier","product":"webhookd","versions":[{"version":"< 1.22","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","baseScore":6.5,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"NONE"},"exploitabilityScore":3.9,"impactScore":2.5}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-09-16T15:38:31.622911Z","id":"CVE-2026-59157","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-290"},{"lang":"en","value":"CWE-807"}]}],"references":[{"url":"https://github.com/ncarlier/webhookd/commit/5ac66677bf7224191f1dfc51a875b09187d10beb","source":"security-advisories@github.com"},{"url":"https://github.com/ncarlier/webhookd/pull/121","source":"security-advisories@github.com"},{"url":"https://github.com/ncarlier/webhookd/releases/tag/v1.22.0","source":"security-advisories@github.com"},{"url":"https://github.com/ncarlier/webhookd/security/advisories/GHSA-v25g-mvwr-f5fp","source":"security-advisories@github.com"}]}