CVE-2023-43810 opentelemetry-instrumentation Denial of Service vulnerability due to unbound cardinality metrics
Attackers can cause memory exhaustion in instrumented applications by sending requests with random, long HTTP methods, 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-2023-43810?
CVE-2023-43810 is a high-severity denial of service vulnerability in open-telemetry opentelemetry-python-contrib, published on 6 Oct 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
OpenTelemetry, also known as OTel for short, is a vendor-neutral open-source Observability framework for instrumenting, generating, collecting, and exporting telemetry data such as traces, metrics, logs. Autoinstrumentation out of the box adds the label `http_method` that has unbound cardinality. It leads to the server's potential memory exhaustion when many malicious requests are sent. HTTP method for requests can be easily set by an attacker to be random and long. In order to be affected program has to be instrumented for HTTP handlers and does not filter any unknown HTTP methods on the level of CDN, LB, previous middleware, etc. This issue has been patched in version 0.41b0.
Weakness: CWE-400
Which versions are affected by CVE-2023-43810?
3 open source packages ship an affected version, including opentelemetry-instrumentation. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
opentelemetry-instrumentation PyPI | All versions | 0.41b0 |
opentelemetry-instrumentation PyPI | All versions | 0.41b0 |
opentelemetry-instrumentation PyPI | All versions | 0.41b0 |
Products include Opentelemetry Opentelemetry.
How do I fix CVE-2023-43810?
Upgrade opentelemetry-instrumentation to 0.41b0 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-2023-43810 being exploited?
There is no known exploitation of CVE-2023-43810 in the wild and no public exploit code.
Other vulnerabilities in open-telemetry opentelemetry-python-contrib
- CVE-2026-29181 OpenTelemetry-Go multi-value `baggage` header extraction causes excessive allocations (remote dos amplification)
- 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-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 GHSA-5rv5-6h4r-h22v, PYSEC-2026-1752, ROOT-APP-PYPI-CVE-2023-43810.