OpenTelemetry eBPF Instrumentation: Java TLS ioctl kprobe allows kernel memory disclosure

Exploitation

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

CVSS

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

EPSS

• CVE-2026-45683: 0.17% estimated exploitation activity in the next 30 days; percentile 6.95 (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 The Java TLS ioctl probe reads user-controlled ioctl pointers with bpfproberead instead of bpfprobereaduser. An instrumented local process can therefore point OBI at kernel memory and cause that memory to be copied into telemetry. Details The vulnerable path is in bpf/generictracer/javatls.c. The kprobe hooks dovfsioctl, filters on fd == 0 and the Java TLS magic command, and then treats the third ioctl argument as a structured buffer. It reads fields from that pointer using bpfproberead, including: - the operation byte from arg - connection metadata from arg + 1 - the payload length from arg + 1 + sizeof(connectioninfot) If len 0, it computes buf = arg + 1 + sizeof(connectioninfot) + sizeof(u32) and passes that pointer into handlebufwithconnection. The next stage, bpf/generictracer/ktracerdefs.h, uses bpfproberead(args-smallbuf, MINHTTP2SIZE, (void )args-ubuf); on the supplied pointer and tail-calls deeper protocol logic. The HTTP protocol path then reads from ubuf and emits…

Published by the source

18 May 2026, 20:12 UTC

Last modified by the source

9 Jun 2026, 10:58 UTC

Source last checked

26 Oct 2026, 15:23 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-fjq3-ffvr-vm46

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# Patch Next advisory brief: CVE-2026-45683

Advisory: OpenTelemetry eBPF Instrumentation: Java TLS ioctl kprobe allows kernel memory disclosure
IDs: CVE-2026-45683, GHSA-fjq3-ffvr-vm46
Record: https://patchnext.com/advisories/cve-2026-45683 (revision 1, source checked 26 Oct 2026, 15:23 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 3.8)
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 0.9.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go go.opentelemetry.io/obi: affected < 0.9.0; fixed in 0.9.0

## 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-fjq3-ffvr-vm46 (GitHub-reviewed advisory GHSA-fjq3-ffvr-vm46 lists affected ranges: Go go.opentelemetry.io/obi >=0 <0.9.0)

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