CVE-2026-41433: OpenTelemetry eBPF Instrumentation arbitrary file overwrite in Java injector

CVE-2026-41433 · Severity: high · CVSS 8.4 · Published 2026-04-24

OpenTelemetry eBPF Instrumentation is a tool used to monitor application performance at the system level. A security flaw in how it handles Java applications allows a local user to trick the monitoring tool into overwriting critical system files. This could allow an attacker to disrupt services, corrupt system integrity, or potentially gain higher administrative privileges on the host machine.

Technologies: go.opentelemetry.io/obi (Go), Opentelemetry eBPF Instrumentation. Vendors: Go, Opentelemetry.

Quick answers

Is CVE-2026-41433 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-41433 being exploited in the wild.
How severe is CVE-2026-41433?
High severity, with a CVSS score of 8.4, published 24 April 2026.
Which products and versions are affected?
go.opentelemetry.io/obi (Go) >= 0.4.0, < 0.8.0, SEMVER:introduced=0.4.0,fixed=0.8.0; Opentelemetry eBPF Instrumentation >= 0.4.0, < 0.8.0.
Is there a fix for CVE-2026-41433?
Yes. go.opentelemetry.io/obi (Go): upgrade to 0.8.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-41433 attacked?
It is attacked with local access, in a software library.
Am I affected by CVE-2026-41433?
Check whether you run go.opentelemetry.io/obi (Go), Opentelemetry eBPF Instrumentation or Opentelemetry Ebpf Instrumentation at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • go.opentelemetry.io/obi (Go): upgrade to 0.8.0 or later
    go get go.opentelemetry.io/obi@v0.8.0

Technical details

A vulnerability exists in the Java agent staging logic within 'pkg/internal/java/java_inject.go'. The OBI injector improperly trusts the 'TMPDIR' environment variable from target processes and uses 'filepath.Join' with the target's root filesystem. Because 'filepath.Join' discards the root if the joined path is absolute, an attacker can provide a path like '/etc' to escape the intended container/process boundary. Additionally, the injector uses unsafe file creation semantics (O_TRUNC without O_EXCL), allowing attackers to use symlinks to redirect the file write to arbitrary host locations. This can be exploited by a local attacker with low privileges to overwrite files owned by the privileged OBI process. The issue is resolved in version 0.8.0.

Affected products

  • OpenTelemetry OpenTelemetry eBPF Instrumentation (OBI) >= 0.4.0, < 0.8.0

Identifiers

  • CVE-2026-41433
  • GHSA-8gmg-3w2q-65f4
  • GO-2026-5253

Timeline

  • 2026-04-16: patched: Version 0.8.0 released with security hardening
  • 2026-04-16: advisory: GitHub Security Advisory GHSA-8gmg-3w2q-65f4 published
  • 2026-04-24: disclosed: CVE-2026-41433 published to NVD

References

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