CVE-2026-114603

OpenTelemetry Python: Unbounded tracestate parsing in opentelemetry-api

Services accepting untrusted inbound propagation headers may experience increased per-request CPU usage when processing malformed tracestate values. In synchronous servers, this may keep a worker occupied. In asynchronous servers, CPU-intensive parsing may delay other requests handled by the same event loop.

The practical impact depends on the HTTP server, HTTP parser, and any upstream request-header limits. Common servers and proxies may reject oversized headers before they reach the application, while custom carriers or deployments with increased header limits may accept substantially larger values.

Unlike optional propagation formats, W3C Trace Context is part of the default OpenTelemetry Python propagation configuration.

The impact is limited to availability. This issue does not expose or modify telemetry data and does not allow code execution.

Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.

CVE-2026-114603 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 (1.45.1); upgrading removes the vulnerable code path.

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Versions of opentelemetry-api up to and including 1.45.0 are affected.

Upgrade opentelemetry-api to version 1.45.1 or later.

Version 1.45.1 replaces the affected parsing operation with linear-time processing and discards combined tracestate headers longer than 8,192 characters.

1. What is CVE-2026-114603? CVE-2026-114603 is a medium-severity uncontrolled resource consumption vulnerability in opentelemetry-api (pip), affecting versions <= 1.45.0. It is fixed in 1.45.1. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
2. How severe is CVE-2026-114603? CVE-2026-114603 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 versions of opentelemetry-api are affected by CVE-2026-114603? opentelemetry-api (pip) versions <= 1.45.0 is affected.
4. Is there a fix for CVE-2026-114603? Yes. CVE-2026-114603 is fixed in 1.45.1. Upgrade to this version or later.
5. Is CVE-2026-114603 exploitable, and should I be worried? Whether CVE-2026-114603 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-2026-114603 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-2026-114603? Upgrade opentelemetry-api to 1.45.1 or later.