5.3
MEDIUM CVSS 3.1
CVE-2026-114603
OpenTelemetry Python: Unbounded tracestate parsing in opentelemetry-api
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.

INFO

Published Date :

Oct. 22, 2026, 4:17 p.m.

Last Modified :

Oct. 22, 2026, 5:29 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-114603 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM MITRE-CVE
CVSS 3.1 MEDIUM [email protected]
Solution
Update OpenTelemetry Python to version 1.45.1 or later to fix excessive CPU usage.
  • Update OpenTelemetry Python to version 1.45.1 or later.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-114603 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-114603 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-114603 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-114603 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Oct. 22, 2026

    Action Type Old Value New Value
    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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
    Added CWE CWE-400
    Added CWE CWE-1333
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/114xxx/CVE-2026-114603.json">CVE-2026-114603</a>
    Added Reference https://github.com/open-telemetry/opentelemetry-python/blob/main/CHANGELOG.md#version-1451066b1-2026-10-06
    Added Reference https://github.com/open-telemetry/opentelemetry-python/commit/d5224bf4ffdf2aee1b592ad238dcc32ca957f26b
    Added Reference https://github.com/open-telemetry/opentelemetry-python/pull/5749
    Added Reference https://github.com/open-telemetry/opentelemetry-python/releases/tag/v1.45.1
    Added Reference https://github.com/open-telemetry/opentelemetry-python/security/advisories/GHSA-xcq7-p3pf-p88h
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.