OpenTelemetry eBPF Instrumentation: Privileged Java agent injection allows arbitrary host file overwrite via untrusted TMPDIR

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.4 · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H

EPSS

• CVE-2026-41433: 0.19% estimated exploitation activity in the next 30 days; percentile 9.18 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary 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. Remediation Upgrade to https://github.com/open-telemetry/opentelemetry-ebpf-instrumentation/releases/tag/v0.8.0. Details The issue is in the Java agent staging logic in pkg/internal/java/javainject.go. The injector reads TMPDIR from the target process environment in findTempDir(...) and validates it with dirOK(...). In the vulnerable implementation, dirOK(...) used filepath.Join(root, dir), where root is /proc/<pid/root. If dir is an absolute path, filepath.Join discards root, so values such as /etc or /proc/1/root/etc are resolved on the host instead of within the target process root. That validated value is…

Published by the source

17 Apr 2026, 22:21 UTC

Last modified by the source

27 Apr 2026, 16:19 UTC

Source last checked

26 Oct 2026, 15:19 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-8gmg-3w2q-65f4

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# Patch Next advisory brief: CVE-2026-41433

Advisory: OpenTelemetry eBPF Instrumentation: Privileged Java agent injection allows arbitrary host file overwrite via untrusted TMPDIR
IDs: CVE-2026-41433, GHSA-8gmg-3w2q-65f4
Record: https://patchnext.com/advisories/cve-2026-41433 (revision 1, source checked 26 Oct 2026, 15:19 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: go.opentelemetry.io/obi 0.8.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go go.opentelemetry.io/obi: affected >= 0.4.0, < 0.8.0; fixed in 0.8.0

## Suggested inspection (read-only)
- Go go.opentelemetry.io/obi: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on go.opentelemetry.io/obi.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-8gmg-3w2q-65f4 (GitHub-reviewed advisory GHSA-8gmg-3w2q-65f4 lists affected ranges: Go go.opentelemetry.io/obi >=0.4.0 <0.8.0)

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