Vulnerabilities

opentelemetry-js is the OpenTelemetry JavaScript Client. Prior to 2.8.0, W3CBaggagePropagator.extract() in @opentelemetry/core does not enforce size limits when parsing inbound baggage HTTP headers. The W3C Baggage specification recommends a maximum of 8,192 bytes and 180 entries; these limits were only enforced on the outbound (inject()) path, not on the inbound (extract()) path. Parsing oversized baggage causes memory allocation proportional to the header size without any cap. This vulnerability is fixed in 2.8.0.

OpenTelemetry-cpp is the C++ implementation of OpenTelemetry. Prior to release 1.27.0, the OTLP HTTP exporters (traces/metrics/logs) read the full HTTP response into an in-memory vector of bytes without a size cap. This is exploitable for memory exhaustion when the configured collector endpoint is attacker-controlled (or a network attacker can MITM the exporter connection). This vulnerability is fixed in opentelemetry-cpp release 1.27.0.

OpenTelemetry-Go is the Go implementation of OpenTelemetry. Prior to version 0.0.17, `go.opentelemetry.io/otel/schema/v1.0` and `go.opentelemetry.io/otel/schema/v1.1` leaks one file descriptor on each successful `ParseFile` call. `ParseFile` opens the schema file and passes it to `Parse` without closing it; repeated parsing in a long-running process can exhaust the process file descriptor limit and cause denial of service. Exploitation depends on a consuming application exposing repeated schema parsing to an attacker-controlled path. Version 0.0.17 contains a patch for the issue.

OpenTelemetry-Go is the Go implementation of OpenTelemetry. Versions 1.41.0 and 1.43.0 removed raw-length rejection and it causes `Parse` to process arbitrarily large/invalid baggage headers and log errors, enabling DoS via oversized inputs. Versions 1.42.0 and 1.44.0 fix the issue.

OpenTelemetry eBPF Instrumentation provides eBPF instrumentation based on the OpenTelemetry standard. From version 0.1.0 to before version 0.9.0, malformed MongoDB wire messages can trigger uncaught panics in the MongoDB TCP parser, allowing a remote unauthenticated attacker to crash the telemetry agent and cause a denial of service. The parser operates on raw attacker-controlled network payloads before the input is fully validated, so a single crafted message can terminate telemetry collection for the affected process or node. This issue has been patched in version 0.9.0.

opentelemetry-js is the OpenTelemetry JavaScript Client. Prior to 0.217.0, a single malformed HTTP request crashes any Node.js process running the OpenTelemetry JS Prometheus exporter. The metrics endpoint (default 0.0.0.0:9464) has no error handling around URL parsing, so a request with an invalid URI causes an uncaught TypeError that terminates the process. This vulnerability is fixed in 0.217.0.

azureauthextension is the Azure Authenticator Extension. From 0.124.0 to 0.150.0, a server-side authentication bypass in azureauthextension allows any party who holds a single valid Azure access token for any scope the collector's configured identity can mint for to authenticate to any OpenTelemetry receiver that uses auth: azure_auth. The extension's Authenticate method does not validate incoming bearer tokens as JWTs. Instead, it calls its own configured credential to obtain an access token and compares the client's token to the result with string equality — and the scope for that server-side token request is taken from the client-supplied Host header. As a result, a token minted for any Azure resource the service principal has ever been issued a token for (ARM, Graph, Key Vault, Storage, etc.) will authenticate to the collector if the attacker picks a matching Host. Tokens are replayable for the full issued lifetime (commonly several hours for managed identity tokens).

OpenTelemetry.Exporter.OpenTelemetryProtocol is the OTLP (OpenTelemetry Protocol) exporter implementation. From 1.8.0 to 1.15.2, the OTLP disk retry feature in OpenTelemetry.Exporter.OpenTelemetryProtocol silently fell back to Path.GetTempPath() when OTEL_DOTNET_EXPERIMENTAL_OTLP_RETRY=disk was set but OTEL_DOTNET_EXPERIMENTAL_OTLP_DISK_RETRY_DIRECTORY_PATH was not configured. The exporter stored and loaded *.blob files under fixed, signal-named subdirectories (traces, metrics, logs) beneath that shared temporary root path. On multi-user systems where the temporary directory is accessible to other local accounts, this allows an attacker to write crafted *.blob files, read *.blob files written by the application between export failures, or deposit numerous or oversized blob files, degrading retry-loop performance or consuming disk space. This vulnerability is fixed in 1.15.3.

OpenTelemetry.OpAmp.Client is the OpAMP client for OpenTelemetry .NET. Prior to 0.2.0-alpha.1, when receiving responses from the OpAMP server over HTTP, the OpAMP client allocates an unbounded buffer to read all bytes from the server, with no upper-bound on the number of bytes consumed. This could cause memory exhaustion in the consuming application if the configured OpAMP server is attacker-controlled (or a network attacker can MitM the connection) and an extremely large body is returned in the response. This vulnerability is fixed in 0.2.0-alpha.1.

OpenTelemetry.Exporter.OneCollector is a .NET exporter that sends telemetry to a OneCollector back-end over HTTP. In versions 1.15.0 and earlier, when a request to the configured back-end or collector results in an unsuccessful HTTP 4xx or 5xx response, the HttpJsonPostTransport class reads the entire response body into memory with no upper bound on the number of bytes consumed in order to include the error response in operator logs. An attacker who controls the configured endpoint, or who can intercept traffic to it via a man-in-the-middle attack, can return an arbitrarily large response body. This causes unbounded heap allocation in the consuming process, leading to high transient memory pressure, garbage-collection stalls, or an OutOfMemoryException that terminates the process. As a workaround, use network-level controls such as firewall rules, mTLS, or a service mesh to prevent man-in-the-middle attacks on the configured back-end or collector endpoint. This issue is fixed in version 1.15.1, which limits the number of bytes read from the response body in an error condition to 4 MiB.

OpenTelemetry.Resources.Azure is the .NET resource detector for Azure environments. In versions 1.15.0-beta.1 and earlier, the AzureVmMetaDataRequestor class makes HTTP requests to the Azure VM instance metadata service and reads the response body into memory without any size limit. An attacker who controls the configured endpoint, or who can intercept traffic to it via a man-in-the-middle attack, can return an arbitrarily large response body. This causes unbounded heap allocation in the consuming process, leading to high transient memory pressure, garbage-collection stalls, or an OutOfMemoryException that terminates the process. As a workaround, disable the Azure VM resource detector or use network-level controls such as firewall rules, mTLS, or a service mesh to prevent man-in-the-middle attacks on the Azure VM instance metadata endpoint. This issue is fixed in version 1.15.1-beta.1, which streams responses rather than buffering them entirely in memory and ignores responses larger than 4 MiB.

OpenTelemetry.Exporter.Zipkin is the .NET Zipkin exporter for OpenTelemetry. In versions 1.15.2 and earlier, the Zipkin exporter remote endpoint cache accepts unbounded key growth derived from span attributes. In high-cardinality scenarios, a process using Zipkin export for client or producer spans could experience avoidable memory growth under sustained unique remote endpoint values, increasing process memory usage over time and degrading availability. This issue is fixed in version 1.15.3, which introduces a bounded, thread-safe LRU cache for remote endpoints with a fixed maximum size.

OpenTelemetry eBPF Instrumentation provides eBPF instrumentation based on the OpenTelemetry standard. From 0.4.0 to before 0.8.0, a flaw in the Java agent injection path allows a local attacker controlling a Java workload to overwrite arbitrary host files when Java injection is enabled and OBI is running with elevated privileges. The injector trusted TMPDIR from the target process and used unsafe file creation semantics, enabling both filesystem boundary escape and symlink-based file clobbering. This vulnerability is fixed in 0.8.0.

OpenTelemetry dotnet is a dotnet telemetry framework. From 1.13.1 to before 1.15.2, When exporting telemetry to a back-end/collector over gRPC or HTTP using OpenTelemetry Protocol format (OTLP), if the request results in a unsuccessful request (i.e. HTTP 4xx or 5xx), the response is read into memory with no upper-bound on the number of bytes consumed. This could cause memory exhaustion in the consuming application if the configured back-end/collector endpoint is attacker-controlled (or a network attacker can MitM the connection) and an extremely large body is returned by the response. This vulnerability is fixed in 1.15.2.

OpenTelemetry-Go is the Go implementation of OpenTelemetry. From 1.15.0 to 1.42.0, the fix for CVE-2026-24051 changed the Darwin ioreg command to use an absolute path but left the BSD kenv command using a bare name, allowing the same PATH hijacking attack on BSD and Solaris platforms. This vulnerability is fixed in 1.43.0.

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.

OpenTelemetry-Go is the Go implementation of OpenTelemetry. The OpenTelemetry Go SDK in version v1.20.0-1.39.0 is vulnerable to Path Hijacking (Untrusted Search Paths) on macOS/Darwin systems. The resource detection code in sdk/resource/host_id.go executes the ioreg system command using a search path. An attacker with the ability to locally modify the PATH environment variable can achieve Arbitrary Code Execution (ACE) within the context of the application. A fix was released with v1.40.0.

The OpenTelemetry Collector offers a vendor-agnostic implementation on how to receive, process and export telemetry data. An unsafe decompression vulnerability allows unauthenticated attackers to crash the collector via excessive memory consumption. OTel Collector version 0.102.1 fixes this issue. It is also fixed in the confighttp module version 0.102.0 and configgrpc module version 0.102.1.

OpenTelemetry-Go Contrib is a collection of third-party packages for OpenTelemetry-Go. Starting in version 0.37.0 and prior to version 0.46.0, the grpc Unary Server Interceptor out of the box adds labels `net.peer.sock.addr` and `net.peer.sock.port` that have unbound cardinality. It leads to the server's potential memory exhaustion when many malicious requests are sent. An attacker can easily flood the peer address and port for requests. Version 0.46.0 contains a fix for this issue. As a workaround to stop being affected, a view removing the attributes can be used. The other possibility is to disable grpc metrics instrumentation by passing `otelgrpc.WithMeterProvider` option with `noop.NewMeterProvider`.

OpenTelemetry-Go Contrib is a collection of third-party packages for OpenTelemetry-Go. A handler wrapper out of the box adds labels `http.user_agent` and `http.method` that have unbound cardinality. It leads to the server's potential memory exhaustion when many malicious requests are sent to it. HTTP header User-Agent or HTTP method for requests can be easily set by an attacker to be random and long. The library internally uses `httpconv.ServerRequest` that records every value for HTTP `method` and `User-Agent`. In order to be affected, a program has to use the `otelhttp.NewHandler` wrapper and not filter any unknown HTTP methods or User agents on the level of CDN, LB, previous middleware, etc. Version 0.44.0 fixed this issue when the values collected for attribute `http.request.method` were changed to be restricted to a set of well-known values and other high cardinality attributes were removed. As a workaround to stop being affected, `otelhttp.WithFilter()` can be used, but it requires manual careful configuration to not log certain requests entirely. For convenience and safe usage of this library, it should by default mark with the label `unknown` non-standard HTTP methods and User agents to show that such requests were made but do not increase cardinality. In case someone wants to stay with the current behavior, library API should allow to enable it.

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.