A vulnerability affects the baggage propagation implementation in
opentelemetry-api and opentelemetry-extension-trace-propagators. Parsing oversized baggage
causes unbounded memory allocation and CPU consumption. Because baggage is automatically
re-injected into every outgoing request, the effect can fan out to downstream services that
never received the original malicious request.
W3CBaggagePropagator did not enforce any limit on the total size or entry count of the
baggage header. The parser iterated character-by-character through the entire value
regardless of length.JaegerPropagator and OtTracePropagator had the same gap in their respective baggage
extraction paths.The practical availability impact for most deployments is limited. Every major Java HTTP server enforces its own header size limit (Tomcat, Jetty, Netty, Vert.x, and gRPC-Java all default to 8 KiB), constraining what an external attacker can deliver before the application is reached. The risk is higher when transport-layer limits are absent — e.g., a compromised internal service communicating over a non-HTTP or custom transport.
Update to version 1.62.0 or later (#8380). The fix enforces limits consistent with the W3C Baggage specification at the propagator level:
baggage header valuesHeaders that would exceed either limit are dropped at the point the limit is reached; already-extracted valid entries are retained.
Ensure HTTP header size limits are configured at the server or gateway level. Most Java HTTP servers enforce an 8 KiB header limit by default, which mitigates external attack vectors independently of this fix.
{
"github_reviewed_at": "2026-05-14T16:36:04Z",
"github_reviewed": true,
"cwe_ids": [
"CWE-770"
],
"nvd_published_at": null,
"severity": "MODERATE"
}