CVE-2026-50271 json
dd-trace-py: Improper parsing of W3C baggage headers may lead to DoS
published 5mo ago modified 18d ago also EUVD-2026-45329 , GHSA-mw54-j2v2-42hr , PYSEC-2026-3461
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.8%
- EPSS 0.8% chance of exploitation in 30 days, percentile 56%
- public exploits
- 0
- none known
Summary
Datadog dd-trace-py is the Datadog Python APM client. Prior to 4.8.2, Datadog tracing libraries that implement W3C baggage propagation parse incoming baggage HTTP headers without enforcing DD_TRACE_BAGGAGE_MAX_ITEMS or DD_TRACE_BAGGAGE_MAX_BYTES limits on the extract path. 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, causing unbounded CPU and memory consumption and enabling a remote denial of service against HTTP services with baggage propagation enabled. This issue is fixed in version 4.8.2.
Patch / fix
- pypi ddtrace 4.8.2
Is CVE-2026-50271 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 3mo ago
Exploit prediction
0.79% chance of exploitation in the next 30 days, higher than 56% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| GitHub | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| OSV | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | ddtrace | <4.8.2 |
4.8.2 |
Affected products
- DataDog dd-trace-py
Classification
References
- github.com /DataDog/dd-trace-py/pull/17926
- github.com /DataDog/dd-trace-py/commit/9c80faa3dcfe238d008c3b3cd0b8e5dfef0aa4cd
-
github.com
/DataDog/dd-trace-py/security/advisories/GHSA-mw54-j2v2-42hr
web, advisory
- github.com /DataDog/dd-trace-py/releases/tag/v4.8.2
-
github.com
/DataDog/dd-trace-py
package
-
pypi.org
/project/ddtrace
package
-
github.com
/advisories/GHSA-mw54-j2v2-42hr
advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-50271
advisory
Sources
- CVE List CVE-2026-50271
- GitHub Advisory GHSA-mw54-j2v2-42hr
- NVD CVE-2026-50271
- OSV PYSEC-2026-3461
- Maintainer advisory GHSA-mw54-j2v2-42hr
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
The maintainers of DataDog/dd-trace-py published their own advisory on GitHub. Reviewed sources take precedence over it.