{"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":0.54392,"cwe":["CWE-400","CWE-770"],"ingestedAt":"2026-07-15T23:47:19.193Z","slug":"CVE-2026-50271","body":"## Overview\n\n### Impact\nDatadog 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.\nThe 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.\n\n### Patches\nThis is resolved in version 4.8.2 and later of the `dd-trace-py` library\n\n### Workarounds\nIf users cannot upgrade immediately:\n1. Disable `baggage` extraction by removing `baggage` from `DD_TRACE_PROPAGATION_STYLE` (or `DD_TRACE_PROPAGATION_STYLE_EXTRACT` if set independently).\n2. 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`).\n\n\n### Resources\nRelated upstream advisories:\n[opentelemetry-go GHSA-mh2q-q3fh-2475](https://github.com/open-telemetry/opentelemetry-go/security/advisories/GHSA-mh2q-q3fh-2475)\n[opentelemetry-dotnet GHSA-g94r-2vxg-569j](https://github.com/open-telemetry/opentelemetry-dotnet/security/advisories/GHSA-g94r-2vxg-569j)\n\n## Affected packages\n\n- `ddtrace < 4.8.2`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `ddtrace 4.8.2`","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.2,"exploitation":0,"ransomware":0},"changes":[]}