CVE-2026-29181 OpenTelemetry-Go multi-value `baggage` header extraction causes excessive allocations (remote dos amplification)
Attackers can cause excessive CPU and memory allocations in OpenTelemetry-Go by sending multiple baggage headers, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-29181?
CVE-2026-29181 is a high-severity denial of service vulnerability in open-telemetry opentelemetry-go, published on 7 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
OpenTelemetry-Go is the Go implementation of OpenTelemetry. From 1.36.0 to 1.40.0, multi-value baggage: header extraction parses each header field-value independently and aggregates members across values. This allows an attacker to amplify cpu and allocations by sending many baggage: header lines, even when each individual value is within the 8192-byte per-value parse limit. This vulnerability is fixed in 1.41.0.
Weakness: CWE-770
Which versions are affected by CVE-2026-29181?
3 open source packages ship an affected version, including go.opentelemetry.io/otel. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
go.opentelemetry.io/otel Go | From 1.36.0 | 1.41.0 |
go.opentelemetry.io/otel Go | From 1.36.0 | 1.41.0 |
go.opentelemetry.io/otel Go | From 1.36.0 | 1.41.0 |
Products include Opentelemetry Opentelemetry.
How do I fix CVE-2026-29181?
Upgrade go.opentelemetry.io/otel to 1.41.0 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-29181 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-29181 exists.
Other vulnerabilities in open-telemetry opentelemetry-go
- CVE-2023-47108 DoS vulnerability in otelgrpc (uncontrolled resource consumption) due to unbound cardinality metrics
- CVE-2023-45142 OpenTelemetry-Go Contrib has DoS vulnerability in otelhttp due to unbound cardinality metrics
- CVE-2023-43810 opentelemetry-instrumentation Denial of Service vulnerability due to unbound cardinality metrics
- CVE-2026-39883 opentelemetry-go: BSD kenv command not using absolute path enables PATH hijacking
- CVE-2026-24051 OpenTelemetry-Go Affected by Arbitrary Code Execution via PATH Hijacking
Sources
Also known as AZL-82085, AZL-82088, AZL-82094, AZL-82109, AZL-82115, AZL-82211 and 578 more.