opentelemetry-js is the OpenTelemetry JavaScript Client. Prior to 2.8.0, W3CBaggagePropagator.extract() in @opentelemetry/core does not enforce size limits when parsing inbound baggage HTTP headers. The W3C Baggage specification recommends a maximum of 8,192 bytes and 180 entries; these limits were only enforced on the outbound (inject()) path, not on the inbound (extract()) path. Parsing oversized baggage causes memory allocation proportional to the header size without any cap. This vulnerability is fixed in 2.8.0.
OpenTelemetry-cpp is the C++ implementation of OpenTelemetry. Prior to release 1.27.0, the OTLP HTTP exporters (traces/metrics/logs) read the full HTTP response into an in-memory vector of bytes without a size cap. This is exploitable for memory exhaustion when the configured collector endpoint is attacker-controlled (or a network attacker can MITM the exporter connection). This vulnerability is fixed in opentelemetry-cpp release 1.27.0.