# CVE-2026-114603: OpenTelemetry Python ReDoS in W3C tracestate parsing

Source: https://junglewise.ai/threats/cve-2026-114603-opentelemetry-python-provides-the-python-api-and-sdk-for  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-22. Updated: 2026-10-22  
License: CC BY 4.0 with a link back

CVE-2026-114603 · Severity: medium · CVSS 5.3 · Published 2026-10-22

OpenTelemetry Python is a distributed tracing library used to monitor application performance. An attacker can send a specially crafted HTTP header with excessive whitespace that causes the tracestate parser to consume excessive CPU through catastrophic backtracking, disrupting the availability of services using the default W3C Trace Context propagator without requiring authentication.

Technologies: [Opentelemetry-Api](https://junglewise.ai/threats/technologies/opentelemetry-opentelemetry-api). Vendors: [Opentelemetry](https://junglewise.ai/threats/vendors/opentelemetry).

## Quick answers

**Is CVE-2026-114603 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-114603 being exploited in the wild.

**How severe is CVE-2026-114603?** Medium severity, with a CVSS score of 5.3, published 22 October 2026.

**Which products and versions are affected?** Opentelemetry-Api prior to 1.45.1; Opentelemetry-Api <= 1.45.0, ECOSYSTEM:introduced=0,fixed=1.45.1.

**Is there a fix for CVE-2026-114603?** Yes. Opentelemetry-Api: upgrade to 1.45.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-114603 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-114603?** Check whether you run Opentelemetry-Api or Opentelemetry-Api at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Opentelemetry-Api: upgrade to 1.45.1 or later

## Technical details

The TraceState.from_header function in opentelemetry-api uses an unbounded optional-whitespace regular expression to parse W3C tracestate headers, leading to ReDoS (regular expression denial of service). A malformed header with a long run of spaces or tabs without a following comma causes quadratic backtracking before the member-count limit takes effect, allowing an unauthenticated attacker to exhaust CPU on a single request.

## Affected products

- OpenTelemetry opentelemetry-api prior to 1.45.1

## Identifiers

- CVE-2026-114603
- GHSA-xcq7-p3pf-p88h

## Timeline

- 2026-10-22: disclosed
- 2026-10-06: patched

## References

- [https://github.com/open-telemetry/opentelemetry-python/blob/main/CHANGELOG.md](https://github.com/open-telemetry/opentelemetry-python/blob/main/CHANGELOG.md)
- [https://github.com/open-telemetry/opentelemetry-python/commit/d5224bf4ffdf2aee1b592ad238dcc32ca957f26b](https://github.com/open-telemetry/opentelemetry-python/commit/d5224bf4ffdf2aee1b592ad238dcc32ca957f26b)

## Related threats

- [OpenTelemetry Python ReDoS in traceparent parsing](https://junglewise.ai/threats/cve-2026-126360-opentelemetry-python-provides-the-python-api-and-sdk-for)
- [OpenTelemetry dotnet: Excessive memory allocation when parsing OpenTelemetry propagation headers](https://junglewise.ai/threats/cve-2026-40894-opentelemetry-dotnet-excessive-memory-allocation-when-parsing)