CVE-2026-114603 OpenTelemetry Python: Unbounded tracestate parsing in opentelemetry-api
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-114603?
CVE-2026-114603 is a medium-severity vulnerability in open-telemetry opentelemetry-python, published on 22 Oct 2026.
Official 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.
Which versions are affected by CVE-2026-114603?
2 open source packages ship an affected version, including opentelemetry-api.
| Package | Affected | Fixed in |
|---|---|---|
opentelemetry-api PyPI | All versions | 1.45.1 |
opentelemetry-api PyPI | All versions | 1.45.1 |
How do I fix CVE-2026-114603?
Upgrade opentelemetry-api to 1.45.1 or later.
Is CVE-2026-114603 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-114603 exists.
Sources
Also known as DEBIAN-CVE-2026-114603, ECHO-235b-c8bb-c828, GHSA-xcq7-p3pf-p88h, MINI-jj2p-p345-6cmp, MINI-m8gq-62hm-gfh7, UBUNTU-CVE-2026-114603.