CVE-2023-43810

opentelemetry-instrumentation Denial of Service vulnerability due to unbound cardinality metrics

HIGH
7.5
CVSS Score
Published: October 6, 2023 at 01:53 PM UTC
Updated: June 17, 2026 at 06:26 AM UTC
1 product affected across 1 vendorOpentelemetry

Using opentelemetry-python-contrib by open-telemetry?

Get instant alerts when new vulnerabilities affect opentelemetry-python-contrib - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH7.5
Exploit prediction
EPSS 0.8%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.41b0
Affected range stops below 0.41b0, so it looks safe — our inference, not a vendor statement

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-400

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card