{"id":"RUSTSEC-2026-0390","summary":"Pingora forwards client-nominated Connection headers to HTTP/1 upstreams, allowing ACL bypass in specific chained deployments","details":"Pingora versions prior to 0.9.0 passed the downstream request through `upstream_request_filter` and wrote it to HTTP/1 upstreams without removing the client's Connection header, other hop-by-hop headers, or the headers Connection nominated, although RFC 9110 Section 7.6.1 requires intermediaries to remove them. The HTTP/2 upstream path already removed Connection and related HTTP/1-specific headers. A client could therefore nominate a header that the application adds in `upstream_request_filter` (for example, `Connection: keep-alive, X-Forwarded-For`). A downstream HTTP/1 intermediary that honors Connection would then strip the Pingora-added header before it reached the origin.\n\nThis specifically affects chained deployments where an HTTP/1 intermediary between Pingora and the origin processes Connection nominations (for example, Go's `net/http/httputil.ReverseProxy`) and the origin trusts headers added by that intermediary (for example, X-Forwarded-For for IP-based authorization). A remote, unauthenticated attacker can have those headers removed, potentially bypassing authorization. This is the same class of issue as CVE-2022-31813 in Apache HTTP Server.\n\nThis flaw was corrected in commits 28c18e6b6b04dd0bd937234e5950049e6d74cded and ca23f1668eca8e78be7ba62ef0edbd458b40eeee. By default, Pingora now removes hop-by-hop and Connection-nominated headers from upstream requests, and rejects requests whose Connection header nominates Host, X-Forwarded-For, X-Forwarded-Host, X-Forwarded-Proto, or a pseudo-header. This is controlled by `PeerOptions::http_upstream_request_policy`; `HttpUpstreamRequestPolicy::preserve()` restores the old passthrough behavior and should not be used if the origin relies on headers added by Pingora. Users should upgrade to Pingora \u003e= 0.9.0.\n\nNote: Cloudflare CDN customers were unaffected, as no such chained deployment as described above exists with internal Pingora services, and Connection headers are sanitized before arriving at Pingora gateways.","aliases":["CVE-2026-105299","GHSA-vx4q-2c55-cvmg"],"modified":"2026-10-26T11:15:11.361865763Z","published":"2026-10-20T12:00:00Z","database_specific":{"license":"CC0-1.0"},"references":[{"type":"PACKAGE","url":"https://crates.io/crates/pingora-proxy"},{"type":"ADVISORY","url":"https://rustsec.org/advisories/RUSTSEC-2026-0390.html"},{"type":"WEB","url":"https://github.com/cloudflare/pingora/commit/28c18e6b6b04dd0bd937234e5950049e6d74cded"},{"type":"WEB","url":"https://github.com/cloudflare/pingora/commit/ca23f1668eca8e78be7ba62ef0edbd458b40eeee"}],"affected":[{"package":{"name":"pingora-proxy","ecosystem":"crates.io","purl":"pkg:cargo/pingora-proxy"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.0.0-0"},{"fixed":"0.9.0"}]}],"ecosystem_specific":{"affects":{"arch":[],"os":[],"functions":[]},"affected_functions":null},"database_specific":{"categories":[],"cvss":"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","informational":null,"source":"https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0390.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}