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OpenAdvisories
Medium · 5.3 CVE-2026-23886 EUVD-2026-3282GHSA-mvpq-2v8x-ww6g

Swift W3C TraceContext has malformed HTTP header that can cause a crash

Published Jan 19, 2026 · Updated Jan 21, 2026 · Assigned by GitHub_M

Description

Swift W3C TraceContext is a Swift implementation of the W3C Trace Context standard, and Swift OTel is an OpenTelemetry Protocol (OTLP) backend for Swift Log, Swift Metrics, and Swift Distributed Tracing. Prior to Swift W3C TraceContext version 1.0.0-beta.5 and Swift OTel version 1.0.4, a denial-of-service vulnerability due to improper input validation allows a remote attacker to crash the service via a malformed HTTP header. This allows crashing the process with data coming from the network when used with, for example, an HTTP server. Most common way of using Swift W3C Trace Context is through Swift OTel. Version 1.0.0-beta.5 of Swift W3C TraceContext and version 1.0.4 of Swift OTel contain a patch for this issue. As a workaround, disable either Swift OTel or the code that extracts the trace information from an incoming header (such as a `TracingMiddleware`).

Affected products

VendorProductAffectedFixed
swift-otel swift-w3c-trace-context swift-otel < 1.0.4, swift-w3c-trace-context < 1.0.0-beta.5 —

Affected packages

EcosystemPackageAffectedFixedRecord
SwiftURL github.com/swift-otel/swift-otel < 1.0.4 1.0.4 GHSA-mvpq-2v8x-ww6g
SwiftURL github.com/swift-otel/swift-w3c-trace-context < 1.0.0-beta.5 1.0.0-beta.5 GHSA-mvpq-2v8x-ww6g

References