OpenTelemetry Python: Unbounded tracestate parsing in opentelemetry-api

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-114603
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-22 16:17:34 UTC
Updated2026-10-22 16:17:34 UTC
DescriptionOpenTelemetry 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.

Risk And Classification

Primary CVSS: v3.1 5.3 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Problem Types: CWE-400 | CWE-1333 | CWE-400 CWE-400: Uncontrolled Resource Consumption | CWE-1333 CWE-1333: Inefficient Regular Expression Complexity

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
3.1CNADECLARED5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Open-telemetry Opentelemetry-python affected < 1.45.1 Not specified

References

ReferenceSourceLinkTags
github.com/open-telemetry/opentelemetry-python/blob/main/CHANGELOG.md [email protected] github.com
github.com/open-telemetry/opentelemetry-python/security/advisories/GHSA-... [email protected] github.com
github.com/open-telemetry/opentelemetry-python/releases/tag/v1.45.1 [email protected] github.com
github.com/open-telemetry/opentelemetry-python/pull/5749 [email protected] github.com
github.com/open-telemetry/opentelemetry-python/commit/d5224bf4ffdf2aee1b... [email protected] github.com
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