{"id":"CVE-2026-28898","aliases":["EUVD-2026-39533","GHSA-4px2-pw77-vc85"],"status":"published","title":"SwiftNIO HTTP/2: HTTP/2-to-HTTP/1 Request Smuggling via unvalidated :path pseudo-header in HTTP2ToHTTP1Codec","description":"swift-nio-http2's HTTP/2-to-HTTP/1.1 codec did not validate pseudo-header values for control characters before placing them into the translated HTTP/1.1 message. swift-nio-http2 1.44.1 adds validation of all pseudo-header values (:path, :authority, :scheme, :method, and :status) at both the HPACK header validation layer and the HTTP/2-to-HTTP/1.1 translation layer. Requests or responses containing CR, LF, or NUL bytes in any pseudo-header value are now rejected with a connection error. This issue is fixed in swift-nio-http2 1.44.1.","severity":{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"adp","from":"cve"},"epss":{"day":"2026-11-09","score":0.0031,"percentile":0.2409,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-116","CWE-444"],"published":"2026-06-12T15:08:16Z","modified":"2026-10-25T22:10:00Z","fixes":[{"ecosystem":"SwiftURL","package":"github.com/apple/swift-nio-http2","fixed_in":["1.44.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"SwiftURL","package":"github.com/apple/swift-nio-http2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.44.0"}]}]},{"source":"osv","ecosystem":"SwiftURL","package":"github.com/apple/swift-nio-http2","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.44.0"}]}]}],"products":[{"vendor":"apple","product":"swift-nio-http2"},{"vendor":"apple","product":"swiftnio_http\\/2"}],"references":[{"url":"https://github.com/advisories/GHSA-4px2-pw77-vc85","tags":["Third Party Advisory"]},{"url":"https://github.com/apple/swift-nio-http2/security/advisories/GHSA-4px2-pw77-vc85","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-28898","tags":["advisory"]},{"url":"https://github.com/apple/swift-nio-http2/commit/61d1b44f6e4e118792be1cff88ee2bc0267c6f9a","tags":["web"]},{"url":"https://github.com/apple/swift-nio-http2","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-28898","description":"swift-nio-http2's HTTP/2-to-HTTP/1.1 codec did not validate pseudo-header values for control characters before placing them into the translated HTTP/1.1 message. swift-nio-http2 1.44.1 adds validation of all pseudo-header values (:path, :authority, :scheme, :method, and :status) at both the HPACK header validation layer and the HTTP/2-to-HTTP/1.1 translation layer. Requests or responses containing CR, LF, or NUL bytes in any pseudo-header value are now rejected with a connection error. This issue is fixed in swift-nio-http2 1.44.1.","status":"published","published":"2026-06-25T18:36:54.046Z","modified":"2026-06-25T19:28:38.97Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"adp"}],"cwes":["CWE-116"],"updated_at":"2026-11-02T14:20:01.969981Z"}],"euvd":[{"id":"EUVD-2026-39533","description":"swift-nio-http2's HTTP/2-to-HTTP/1.1 codec did not validate pseudo-header values for control characters before placing them into the translated HTTP/1.1 message. swift-nio-http2 1.44.1 adds validation of all pseudo-header values (:path, :authority, :scheme, :method, and :status) at both the HPACK header validation layer and the HTTP/2-to-HTTP/1.1 translation layer. Requests or responses containing CR, LF, or NUL bytes in any pseudo-header value are now rejected with a connection error. This issue is fixed in swift-nio-http2 1.44.1.","status":"published","published":"2026-06-25T18:36:54Z","modified":"2026-06-25T19:28:38Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T18:20:25.316004Z"}],"ghsa":[{"id":"GHSA-4px2-pw77-vc85","title":"SwiftNIO HTTP/2: HTTP/2-to-HTTP/1 Request Smuggling via unvalidated :path pseudo-header in HTTP2ToHTTP1Codec","description":"swift-nio-http2's HTTP/2-to-HTTP/1.1 codec (`HTTP2FramePayloadToHTTP1ServerCodec` / `HTTP2ToHTTP1ServerCodec`) did not validate pseudo-header values for control characters before placing them into the translated HTTP/1.1 message. A remote attacker could send an HTTP/2 request containing CR (\\r), LF (\\n), or NUL (\\0) bytes in pseudo-header values such as `:path`, and when the server translated this to HTTP/1.1 — for example in a reverse-proxy configuration — the resulting output could contain injected headers or entirely smuggled requests.\n\nThis is an HTTP/2-to-HTTP/1.1 request smuggling vulnerability. HTTP/2's binary framing means that CRLF bytes are never parsed as line terminators at the HTTP/2 layer, so they pass through transparently to the HTTP/1.1 output. Any swift-nio-http2 server that translates HTTP/2 requests to HTTP/1.1 and forwards them to a backend is affected. Server-side Swift frameworks such as Vapor that use this codec in a reverse-proxy pattern are directly affected.\n\nThis vulnerability is related to https://github.com/advisories/GHSA-7fj7-39wj-c64f in swift-nio, which addressed CRLF injection in HTTP/1.1 header values but did not cover pseudo-header values in the HTTP/2 layer.\n\nThis vulnerability is also related to https://github.com/advisories/GHSA-cq87-8r7h-962v in swift-nio, which addressed CRLF injection in HTTP/1.1 version, method and path.\n\nswift-nio-http2 1.44.0 adds validation of all pseudo-header values (:path, :authority, :scheme, :method, and :status) at both the HPACK header validation layer and the HTTP/2-to-HTTP/1.1 translation layer. Requests or responses containing CR, LF, or NUL bytes in any pseudo-header value are now rejected with a connection error.\n\nSwiftNIO recommends all adopters upgrade to 1.44.0 as soon as possible.\n\nSwiftNIO thanks @kuranikaran for filing this issue and the support in fixing it.","status":"published","published":"2026-06-12T15:08:16Z","modified":"2026-07-15T21:23:11Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"cwes":["CWE-116","CWE-444"],"updated_at":"2026-11-02T14:40:43.958448Z"}],"nvd":[{"id":"CVE-2026-28898","description":"swift-nio-http2's HTTP/2-to-HTTP/1.1 codec did not validate pseudo-header values for control characters before placing them into the translated HTTP/1.1 message. swift-nio-http2 1.44.1 adds validation of all pseudo-header values (:path, :authority, :scheme, :method, and :status) at both the HPACK header validation layer and the HTTP/2-to-HTTP/1.1 translation layer. Requests or responses containing CR, LF, or NUL bytes in any pseudo-header value are now rejected with a connection error. This issue is fixed in swift-nio-http2 1.44.1.","status":"published","published":"2026-06-25T19:16:36.977Z","modified":"2026-10-25T22:10:00.15Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-116"],"updated_at":"2026-11-02T14:12:26.045561Z"}],"osv":[{"id":"GHSA-4px2-pw77-vc85","title":"SwiftNIO HTTP/2: HTTP/2-to-HTTP/1 Request Smuggling via unvalidated :path pseudo-header in HTTP2ToHTTP1Codec","description":"swift-nio-http2's HTTP/2-to-HTTP/1.1 codec (`HTTP2FramePayloadToHTTP1ServerCodec` / `HTTP2ToHTTP1ServerCodec`) did not validate pseudo-header values for control characters before placing them into the translated HTTP/1.1 message. A remote attacker could send an HTTP/2 request containing CR (\\r), LF (\\n), or NUL (\\0) bytes in pseudo-header values such as `:path`, and when the server translated this to HTTP/1.1 — for example in a reverse-proxy configuration — the resulting output could contain injected headers or entirely smuggled requests.\n\nThis is an HTTP/2-to-HTTP/1.1 request smuggling vulnerability. HTTP/2's binary framing means that CRLF bytes are never parsed as line terminators at the HTTP/2 layer, so they pass through transparently to the HTTP/1.1 output. Any swift-nio-http2 server that translates HTTP/2 requests to HTTP/1.1 and forwards them to a backend is affected. Server-side Swift frameworks such as Vapor that use this codec in a reverse-proxy pattern are directly affected.\n\nThis vulnerability is related to https://github.com/advisories/GHSA-7fj7-39wj-c64f in swift-nio, which addressed CRLF injection in HTTP/1.1 header values but did not cover pseudo-header values in the HTTP/2 layer.\n\nThis vulnerability is also related to https://github.com/advisories/GHSA-cq87-8r7h-962v in swift-nio, which addressed CRLF injection in HTTP/1.1 version, method and path.\n\nswift-nio-http2 1.44.0 adds validation of all pseudo-header values (:path, :authority, :scheme, :method, and :status) at both the HPACK header validation layer and the HTTP/2-to-HTTP/1.1 translation layer. Requests or responses containing CR, LF, or NUL bytes in any pseudo-header value are now rejected with a connection error.\n\nSwiftNIO recommends all adopters upgrade to 1.44.0 as soon as possible.\n\nSwiftNIO thanks @kuranikaran for filing this issue and the support in fixing it.","status":"published","published":"2026-06-12T15:08:16Z","modified":"2026-07-29T05:15:34.230069609Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"cwes":["CWE-116","CWE-444"],"updated_at":"2026-11-02T15:46:37.148947Z"}]}}