OpenTelemetry Python provides the Python API and SDK for OpenTelemetry. Prior to 1.45.1, the opentelemetry-api function TraceState.from_header in opentelemetry/trace/span.py, reached through TraceContextTextMapPropagator.extract, parses inbound W3C tracestate headers with an unbounded optional-whitespace regular expression. A malformed header containing a long run of spaces or tabs without a following comma causes quadratic backtracking before the member-count limit is applied. Services using the default W3C Trace Context propagator can therefore spend excessive CPU time on one unauthenticated request when the HTTP server, parser, gateway, or custom carrier accepts a sufficiently large header. The processing can occupy a synchronous worker or delay unrelated requests on the same asynchronous event loop. The impact is limited to availability and does not expose or modify telemetry data or allow code execution. This issue is fixed in version 1.45.1.
History

Thu, 29 Oct 2026 03:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 23 Oct 2026 00:45:00 +0000

Type Values Removed Values Added
First Time appeared Opentelemetry
Opentelemetry opentelemetry-python
Vendors & Products Opentelemetry
Opentelemetry opentelemetry-python
References
Metrics threat_severity

None

threat_severity

Moderate


Thu, 22 Oct 2026 15:45:00 +0000

Type Values Removed Values Added
Description OpenTelemetry Python provides the Python API and SDK for OpenTelemetry. Prior to 1.45.1, the opentelemetry-api function TraceState.from_header in opentelemetry/trace/span.py, reached through TraceContextTextMapPropagator.extract, parses inbound W3C tracestate headers with an unbounded optional-whitespace regular expression. A malformed header containing a long run of spaces or tabs without a following comma causes quadratic backtracking before the member-count limit is applied. Services using the default W3C Trace Context propagator can therefore spend excessive CPU time on one unauthenticated request when the HTTP server, parser, gateway, or custom carrier accepts a sufficiently large header. The processing can occupy a synchronous worker or delay unrelated requests on the same asynchronous event loop. The impact is limited to availability and does not expose or modify telemetry data or allow code execution. This issue is fixed in version 1.45.1.
Title OpenTelemetry Python: Unbounded tracestate parsing in opentelemetry-api
Weaknesses CWE-1333
CWE-400
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-10-22T15:29:25.108Z

Updated: 2026-10-29T02:17:42.817Z

Reserved: 2026-10-21T20:34:25.599Z

Link: CVE-2026-114603

cve-icon Vulnrichment

Updated: 2026-10-29T02:17:37.271Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-22T16:17:34.860

Modified: 2026-10-29T04:18:24.130

Link: CVE-2026-114603

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-22T15:29:25Z

Links: CVE-2026-114603 - Bugzilla