How severe is CVE-2026-50273?

CVE-2026-50273 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-50273?

CVE-2026-50273 affects the following packages: Datadog.Trace (NuGet), Datadog.Trace.OpenTracing (NuGet). Ecosystems affected: NuGet.

How do I fix CVE-2026-50273?

Update Datadog.Trace to 3.43.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-50273 is resolved across your whole dependency graph.

How do I detect CVE-2026-50273 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Datadog.Trace, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-50273 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2026-50273 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-50273 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-50273?

CVE-2026-50273 has an EPSS (Exploit Prediction Scoring System) score of 0.8%, placing it in the 55th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-50273?

CVE-2026-50273 is classified as CWE-770 (CWE-770). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-50273 published, and has it been updated?

CVE-2026-50273 was published on July 17, 2026 and was last updated on August 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

.NET

.NET NuGet

Not in CISA KEV

HIGH severity

CVE-2026-50273 — Datadog.Trace

HIGHFix: DataDog/dd-trace-dotnet@38092e0

CVE-2026-50273 is a high-severity (CVSS 7.5) CWE-770 vulnerability in Datadog.Trace. A fix is available for Datadog.Trace — see the affected versions and patch details below.

Datadog .NET Tracer: Improper parsing of W3C baggage headers may lead to DoS

Also known asGHSA-38wr-vpc7-2mp4

Published

Jul 17, 2026

Updated

Aug 12, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Oct 16, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-50273.

EPSS Exploitation Probability

via FIRST.org ↗

0.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs55th percentile — riskier than 55% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-50273 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 390,400 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

2 pkgs affected

.NETDatadog.Trace.NETDatadog.Trace.OpenTracing

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.

Description

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 3.43.0 and later of the dd-trace-dotnet library.

Workarounds

If users cannot upgrade immediately:

Disable baggage extraction by removing baggage from DD_TRACE_PROPAGATION_STYLE (or DD_TRACE_PROPAGATION_STYLE_EXTRACT if set independently).
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

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`Datadog.Trace`	all versions	3.43.0`dotnet add package Datadog.Trace --version 3.43.0`
.NETNuGet	`Datadog.Trace.OpenTracing`	all versions	3.43.0`dotnet add package Datadog.Trace.OpenTracing --version 3.43.0`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Datadog.Trace, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Datadog.Trace to 3.43.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-50273 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

### 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 unbounde