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OpenAdvisories
Medium · 5.3 CVE-2026-28898 EUVD-2026-39533GHSA-4px2-pw77-vc85

SwiftNIO HTTP/2: HTTP/2-to-HTTP/1 Request Smuggling via unvalidated :path pseudo-header in HTTP2ToHTTP1Codec

Published Jun 25, 2026 · Updated Jun 25, 2026 · Assigned by apple

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.

Affected products

VendorProductAffectedFixed
Apple swift-nio-http2 < 1.44.1 1.44.1

Affected packages

EcosystemPackageAffectedFixedRecord
SwiftURL github.com/apple/swift-nio-http2 < 1.44.0 1.44.0 GHSA-4px2-pw77-vc85

References