Affected: open-telemetry opentelemetry-go, Red Hat Cert Manager support for Red Hat OpenShift release 1.19, Red Hat Cluster Observability Operator 1.5.0, Red Hat Logging Subsystem for Red Hat OpenShift 6.6, Red Hat multicluster engine for Kubernetes 2.11, Red Hat multicluster engine for Kubernetes 2.8, Red Hat cert-manager Operator for Red Hat OpenShift, Red Hat Multicluster Engine for Kubernetes, Red Hat Advanced Cluster Management for Kubernetes 2

OpenTelemetry-Go is the Go implementation of OpenTelemetry. From 1.36.0 to 1.40.0, multi-value baggage: header extraction parses each header field-value independently and aggregates members across values. This allows an attacker to amplify cpu and allocations by sending many baggage: header lines, even when each individual value is within the 8192-byte per-value parse limit. This vulnerability is fixed in 1.41.0.

Affected: Go: go.opentelemetry.io/otel

multi-value `baggage:` header extraction parses each header field-value independently and aggregates members across values. this allows an attacker to amplify cpu and allocations by sending many `baggage:` header lines, even when each individual value is within the 8192-byte per-value parse limit.

## severity

HIGH (availability / remote request amplification)

## relevant links

- repository: https://github.com/open-telemetry/opentelemetry-go - pinned callsite: https://github.com/open-telemetry/opentelemetry-go/blob/1ee4a4126dbdd1bc79e9fae072fa488beffac52a/propagation/baggage.go#L58

## vulnerability details

**pins:** open-telemetry/opentelemetry-go@1ee4a4126dbdd1bc79e9fae072fa488beffac52a **as-of:** 2026-02-04 **policy:** direct (no program scope provided)

**callsite:** propagation/baggage.go:58 (`extractMultiBaggage`) **attacker control:** inbound HTTP request headers (many `baggage` field-values) → `propagation.HeaderCarrier.Values("baggage")` → repeated `baggage.Parse` + member aggregation

### root cause

`extractMultiBaggage` iterates over all `baggage` header field-values and parses each one independently, then appends members into a shared slice. the 8192-byte parsing cap applies per header value, but the multi-value path repeats that work once per header line (bounded only by the server/proxy header byte limit).

### impact

in a default `net/http` configuration (max header bytes 1mb), a single request with many `baggage:` header field-values can cause large per…