dd-trace-rb: Improper parsing of W3C baggage headers may lead to DoS

published 2026-07-15 3 mo ago modified 2026-09-25 44 d ago also GHSA-p5f6-rccc-jv98 , EUVD-2026-77671

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

dd-trace-rb is Datadog's client library for Ruby. Prior to 2.32.0, W3C baggage extraction does not enforce DD_TRACE_BAGGAGE_MAX_ITEMS, which defaults to 64, or DD_TRACE_BAGGAGE_MAX_BYTES, which defaults to 8192, although those limits apply during baggage injection. A remote unauthenticated attacker can send a baggage HTTP header containing many comma-separated key-value pairs or a single very large value. The extraction path allocates entries while parsing the attacker-controlled header on every request, causing unbounded CPU and memory consumption in an HTTP service where the baggage propagation style is enabled, which is the default for most affected tracers. This can cause denial of service. This issue is fixed in version 2.32.0.

Patch / fix

fixed in 1 links 3

rubygems datadog 2.32.0

github.com/DataDog/dd-trace-rb@3619470 commit
github.com/DataDog/dd-trace-rb#5672 pull request
github.com/DataDog/dd-trace-rb/releases/tag/v2.32.0 release

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 55 d ago (2026-09-14)

Exploit prediction

0.79% chance of exploitation in the next 30 days, higher than 56% of all scored CVEs (FIRST EPSS, 2026-11-08).

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

Affected packages

ecosystem	package	affected	fixed in
rubygems	datadog	<2.32.0	2.32.0

Affected products

DataDog dd-trace-rb

Classification

Weakness

CWE-770 Allocation of Resources Without Limits or Throttling
CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns 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.

Summary