OpenTelemetry Python up to 1.45.1 TraceContextTextMapPropagator TraceContextTextMapPropagator.extract redos

Summaryinfo

A vulnerability labeled as problematic has been found in OpenTelemetry Python up to 1.45.1. Affected by this issue is the function TraceContextTextMapPropagator.extract of the component TraceContextTextMapPropagator. Executing a manipulation can lead to redos. This vulnerability appears as CVE-2026-126360. The attack may be performed from remote. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability has been found in OpenTelemetry Python up to 1.45.1 and classified as problematic. This vulnerability affects the function TraceContextTextMapPropagator.extract of the component TraceContextTextMapPropagator. The manipulation with an unknown input leads to a redos vulnerability. The CWE definition for the vulnerability is CWE-1333. The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential. As an impact it is known to affect availability. CVE summarizes:

OpenTelemetry Python provides the Python API and SDK for OpenTelemetry. Prior to 1.45.2, TraceContextTextMapPropagator.extract() in opentelemetry-api can perform quadratic-time regular-expression backtracking on a malformed traceparent value containing a trace-context prefix, a long whitespace sequence, and an embedded newline. Exploitation requires an attacker-controlled carrier that preserves embedded newlines and permits a sufficiently large value, because conforming HTTP header values cannot contain embedded newlines. JSON-based carriers, including applicable MCP request metadata integrations, can preserve the required newline depending on the SDK, instrumentation, and message-size limits. Parsing on an asynchronous server's event-loop thread can consume excessive CPU and delay unrelated requests, while the advisory does not establish disclosure, modification, or code execution. This issue is fixed in version 1.45.2.

The advisory is available at github.com. This vulnerability was named CVE-2026-126360 since 11/10/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1449.003 by the MITRE ATT&CK project.

Upgrading to version 1.45.2 eliminates this vulnerability.

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Productinfo

Type

• Programming Language Software

Vendor

• OpenTelemetry

Name

• Python

Version

• 1.45.0
• 1.45.1

License

• open-source

CPE 2.3info

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• 🔒

CPE 2.2info

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• 🔒

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