---
id: CVE-2026-50271
aliases:
  - GHSA-mw54-j2v2-42hr
  - PYSEC-2026-3461
title: 'dd-trace-py: Improper parsing of W3C baggage headers may lead to DoS'
summary: 'dd-trace-py: Improper parsing of W3C baggage headers may lead to DoS'
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
vendor: ddtrace
product: ddtrace
ecosystem: pip
affected:
  - ddtrace < 4.8.2
patched:
  - ddtrace 4.8.2
published: '2026-07-15'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:50:12.623722840Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-mw54-j2v2-42hr'
references:
  - url: >-
      https://github.com/DataDog/dd-trace-py/security/advisories/GHSA-mw54-j2v2-42hr
  - url: 'https://github.com/DataDog/dd-trace-py'
  - url: 'https://github.com/advisories/GHSA-mw54-j2v2-42hr'
tags:
  - osv
  - pip
  - ghsa
epss: 0.00793
epssPercentile: 0.5487
cwe:
  - CWE-400
  - CWE-770
ingestedAt: '2026-07-15T23:47:19.193Z'
---

## Overview

### Impact
Datadog tracing libraries that implement W3C baggage propagation parse incoming baggage HTTP headers without enforcing item-count or byte-size limits on the extract path. The DD_TRACE_BAGGAGE_MAX_ITEMS (default 64) and DD_TRACE_BAGGAGE_MAX_BYTES (default 8192) limits were applied only to baggage injection, not extraction. A remote, unauthenticated attacker can send a request whose baggage header contains an arbitrarily large number of comma-separated key-value pairs (or a single very large value). The tracer allocates a hash-map entry for each pair on every request, causing unbounded CPU and memory consumption and enabling a remote Denial of Service against any HTTP service that has the baggage propagation style enabled.
The baggage propagation style is enabled by default in most affected tracers, so any internet-facing service that has been instrumented with an affected tracer version is exposed unless the propagation style has been explicitly narrowed.

### Patches
This is resolved in version 4.8.2 and later of the `dd-trace-py` library

### Workarounds
If users cannot upgrade immediately:
1. Disable `baggage` extraction by removing `baggage` from `DD_TRACE_PROPAGATION_STYLE` (or `DD_TRACE_PROPAGATION_STYLE_EXTRACT` if set independently).
2. Cap the maximum HTTP request header size at an upstream proxy or web server (for example, Apache `LimitRequestFieldSize`, Nginx `large_client_header_buffers`, Envoy `max_request_headers_kb`).


### Resources
Related upstream advisories:
[opentelemetry-go GHSA-mh2q-q3fh-2475](https://github.com/open-telemetry/opentelemetry-go/security/advisories/GHSA-mh2q-q3fh-2475)
[opentelemetry-dotnet GHSA-g94r-2vxg-569j](https://github.com/open-telemetry/opentelemetry-dotnet/security/advisories/GHSA-g94r-2vxg-569j)

## Affected packages

- `ddtrace < 4.8.2`

## Remediation

Upgrade to a patched release:

- `ddtrace 4.8.2`