CVE-2026-45292

Overview

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.

Technical Details

• 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 W3C Baggage specification recommends a maximum of 8,192 bytes and 180 entries; none of
  these limits were enforced.

Workarounds

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.

References

• W3C Baggage Specification §Limits

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.

The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap. Typical impact: resource exhaustion leading to denial of service.

CVE-2026-45292 has a CVSS score of 5.3 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.62.0); upgrading removes the vulnerable code path.

Kodem intelligence

Update to version 1.62.0 or later (#8380).
The fix enforces limits consistent with the W3C Baggage specification at the propagator level:

• Maximum total baggage size: 8,192 bytes across all baggage header values
• Maximum number of entries: 64

Headers that would exceed either limit are dropped at the point the limit is reached;
already-extracted valid entries are retained.

1. What is CVE-2026-45292? CVE-2026-45292 is a medium-severity allocation of resources without limits or throttling vulnerability in io.opentelemetry:opentelemetry-api (maven), affecting versions <= 1.61.0. It is fixed in 1.62.0. The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap.
2. How severe is CVE-2026-45292? CVE-2026-45292 has a CVSS score of 5.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which packages are affected by CVE-2026-45292?
   • io.opentelemetry:opentelemetry-api (maven) (versions <= 1.61.0)
   • io.opentelemetry:opentelemetry-extension-trace-propagators (maven) (versions <= 1.61.0)
4. Is there a fix for CVE-2026-45292? Yes. CVE-2026-45292 is fixed in 1.62.0. Upgrade to this version or later.
5. Is CVE-2026-45292 exploitable, and should I be worried? Whether CVE-2026-45292 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-45292 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-45292?
   • Upgrade io.opentelemetry:opentelemetry-api to 1.62.0 or later
   • Upgrade io.opentelemetry:opentelemetry-extension-trace-propagators to 1.62.0 or later