CVE-2026-50271 | dd-trace-py: Improper parsing of W3C baggage headers may lead to DoS

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.

Published: 2026-07-17 Last update: 2026-07-20 Assigner: [email protected] Source: [email protected]
NVD Status：Received，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-50271 is rated Moderate Risk (49/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.79%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-50271

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-07-18 0.11% 0.79% +0.69%
2 2026-06-12 — 0.11% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-50271

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2026-50271

GitHub Security Advisory for CVE-2026-50271

GHSA-mw54-j2v2-42hr · Severity: high · Ecosystem: pip — dd-trace-py: Improper parsing of W3C baggage headers may lead to DoS

Affected software / configurations for CVE-2026-50271

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-50271

cvelogic Threat Intelligence