Answer in brief
CVE-2026-33701 records a Critical severity (CVSS 9.8) deserialization vulnerability in OpenTelemetry: Unsafe Deserialization in RMI Instrumentation may Lead to Remote Code Execution. The source record does not mark it as known exploited. 1 affected package is mapped in the feed.
Answer in brief
CVE-2026-33701 records a Critical severity (CVSS 9.8) deserialization vulnerability in OpenTelemetry: Unsafe Deserialization in RMI Instrumentation may Lead to Remote Code Execution. The source record does not mark it as known exploited. 1 affected package is mapped in the feed.
Update io.opentelemetry.javaagent:opentelemetry-javaagent to 2.26.1 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanDeserialization describes the vulnerability class recorded for this advisory. The current record does not mark CVE-2026-33701 as known exploited; continue to monitor the source for status changes. The feed includes package mappings that can be checked against lockfiles and deployed manifests.
| Package | Affected range | Fixed version |
|---|---|---|
| io.opentelemetry.javaagent:opentelemetry-javaagentmaven | <2.26.1 | 2.26.1 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
CVE-2026-33701 records a Critical severity (CVSS 9.8) deserialization vulnerability in OpenTelemetry: Unsafe Deserialization in RMI Instrumentation may Lead to Remote Code Execution. The source record does not mark it as known exploited. 1 affected package is mapped in the feed.
The source record does not mark it as known exploited.
Check lockfiles and deployed manifests for io.opentelemetry.javaagent:opentelemetry-javaagent.
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL GuardUpdate io.opentelemetry.javaagent:opentelemetry-javaagent to 2.26.1 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanDeserialization describes the vulnerability class recorded for this advisory. The current record does not mark CVE-2026-33701 as known exploited; continue to monitor the source for status changes. The feed includes package mappings that can be checked against lockfiles and deployed manifests.
| Package | Affected range | Fixed version |
|---|---|---|
| io.opentelemetry.javaagent:opentelemetry-javaagentmaven | <2.26.1 | 2.26.1 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
CVE-2026-33701 records a Critical severity (CVSS 9.8) deserialization vulnerability in OpenTelemetry: Unsafe Deserialization in RMI Instrumentation may Lead to Remote Code Execution. The source record does not mark it as known exploited. 1 affected package is mapped in the feed.
The source record does not mark it as known exploited.
Check lockfiles and deployed manifests for io.opentelemetry.javaagent:opentelemetry-javaagent.
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL GuardOpenTelemetry Java Instrumentation provides OpenTelemetry auto-instrumentation and instrumentation libraries for Java. In versions prior to 2.26.1, the RMI instrumentation registered a custom endpoint that deserialized incoming data without applying serialization filters. On JDK version 16 and earlier, an attacker with network access to a JMX or RMI port on an instrumented JVM could exploit this to potentially achieve remote code execution. All three of the following conditions must be true to exploit this vulnerability: First, OpenTelemetry Java instrumentation is attached as a Java agent (`-javaagent`) on Java 16 or earlier. Second, JMX/RMI port has been explicitly configured via `-Dcom.sun.management.jmxremote.port` and is network-reachable. Third, gadget-chain-compatible library is present on the classpath. This results in arbitrary remote code execution with the privileges of the user running the instrumented JVM. For JDK >= 17, no action is required, but upgrading is strongly encouraged. For JDK < 17, upgrade to version 2.26.1 or later. As a workaround, set the system property `-Dotel.instrumentation.rmi.enabled=false` to disable the RMI integration.
OpenTelemetry Java Instrumentation provides OpenTelemetry auto-instrumentation and instrumentation libraries for Java. In versions prior to 2.26.1, the RMI instrumentation registered a custom endpoint that deserialized incoming data without applying serialization filters. On JDK version 16 and earlier, an attacker with network access to a JMX or RMI port on an instrumented JVM could exploit this to potentially achieve remote code execution. All three of the following conditions must be true to exploit this vulnerability: First, OpenTelemetry Java instrumentation is attached as a Java agent (`-javaagent`) on Java 16 or earlier. Second, JMX/RMI port has been explicitly configured via `-Dcom.sun.management.jmxremote.port` and is network-reachable. Third, gadget-chain-compatible library is present on the classpath. This results in arbitrary remote code execution with the privileges of the user running the instrumented JVM. For JDK >= 17, no action is required, but upgrading is strongly encouraged. For JDK < 17, upgrade to version 2.26.1 or later. As a workaround, set the system property `-Dotel.instrumentation.rmi.enabled=false` to disable the RMI integration.