{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-9697: undici vulnerable to TLS certificate validation bypass via dropped requestTls in SOCKS5 ProxyAgent","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-9697","status":"final","version":"1","initial_release_date":"2026-06-17T16:46:42.706Z","current_release_date":"2026-06-17T18:34:54.144Z","revision_history":[{"date":"2026-06-17T16:46:42.706Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"Impact:\nundici's ProxyAgent silently drops the requestTls option when configured with a SOCKS5 proxy URI (socks5:// or socks://). The target HTTPS connection through the SOCKS5 tunnel falls back to Node's default trust store, ignoring user-configured ca, cert, key, rejectUnauthorized, and servername settings.\n\nApplications that pin to an internal or corporate CA via requestTls.ca will, when their proxy URI is SOCKS5, get the default Mozilla CA bundle as the trust anchor instead. Any cert signed by any publicly-trusted CA for the target hostname is accepted, breaking the intended pin and enabling MITM read and tamper of the HTTPS exchange.\n\nAffected applications are those that use undici's ProxyAgent (or Socks5ProxyAgent directly) with SOCKS5 AND rely on requestTls for TLS scope restriction. The bug was introduced in undici 7.23.0 when SOCKS5 support was added.\n\nPatches:\nUpgrade to undici v7.28.0 or v8.5.0.\n\nWorkarounds:\nNo workaround is available within the SOCKS5 path. If a SOCKS5 proxy with TLS scope restriction is required and an upgrade is not yet possible, route the traffic through an HTTP-proxy ProxyAgent instead, where requestTls is honored correctly.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-9697 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-9697"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-9697"},{"category":"external","summary":"github.com","url":"https://github.com/nodejs/undici/security/advisories/GHSA-vmh5-mc38-953g"},{"category":"external","summary":"cna.openjsf.org","url":"https://cna.openjsf.org/security-advisories.html"}]},"product_tree":{"branches":[{"category":"vendor","name":"undici","branches":[{"category":"product_name","name":"undici","branches":[{"category":"product_version_range","name":">=7.23.0 <7.28.0","product":{"name":"undici undici >=7.23.0 <7.28.0","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:undici:undici:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=8.0.0 <8.5.0","product":{"name":"undici undici >=8.0.0 <8.5.0","product_id":"CSAFPID-2","product_identification_helper":{"cpe":"cpe:2.3:a:undici:undici:*:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"7.28.0","product":{"name":"undici undici 7.28.0","product_id":"CSAFPID-3","product_identification_helper":{"cpe":"cpe:2.3:a:undici:undici:*:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"8.5.0","product":{"name":"undici undici 8.5.0","product_id":"CSAFPID-4","product_identification_helper":{"cpe":"cpe:2.3:a:undici:undici:*:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-9697","title":"undici vulnerable to TLS certificate validation bypass via dropped requestTls in SOCKS5 ProxyAgent","notes":[{"category":"description","text":"Impact:\nundici's ProxyAgent silently drops the requestTls option when configured with a SOCKS5 proxy URI (socks5:// or socks://). The target HTTPS connection through the SOCKS5 tunnel falls back to Node's default trust store, ignoring user-configured ca, cert, key, rejectUnauthorized, and servername settings.\n\nApplications that pin to an internal or corporate CA via requestTls.ca will, when their proxy URI is SOCKS5, get the default Mozilla CA bundle as the trust anchor instead. Any cert signed by any publicly-trusted CA for the target hostname is accepted, breaking the intended pin and enabling MITM read and tamper of the HTTPS exchange.\n\nAffected applications are those that use undici's ProxyAgent (or Socks5ProxyAgent directly) with SOCKS5 AND rely on requestTls for TLS scope restriction. The bug was introduced in undici 7.23.0 when SOCKS5 support was added.\n\nPatches:\nUpgrade to undici v7.28.0 or v8.5.0.\n\nWorkarounds:\nNo workaround is available within the SOCKS5 path. If a SOCKS5 proxy with TLS scope restriction is required and an upgrade is not yet possible, route the traffic through an HTTP-proxy ProxyAgent instead, where requestTls is honored correctly.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1","CSAFPID-2"],"fixed":["CSAFPID-3","CSAFPID-4"]},"scores":[{"cvss_v3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","baseScore":7.4,"baseSeverity":"HIGH"},"products":["CSAFPID-1","CSAFPID-2"]}],"remediations":[{"category":"vendor_fix","details":"Update to a fixed version: 7.28.0, 8.5.0.","product_ids":["CSAFPID-1","CSAFPID-2"]}]}]}