CVE-2026-45686: OpenTelemetry eBPF Instrumentation integer overflow in Memcached parser

CVE-2026-45686 · Severity: high · CVSS 7.5 · Published 2026-06-02

OpenTelemetry eBPF Instrumentation (OBI) is a tool used to monitor and collect performance data from applications without requiring manual code changes. A vulnerability in its Memcached protocol parser allows a remote attacker to crash the monitoring process by sending a specially crafted request to an instrumented service. This results in a denial of service for the monitoring system, causing a loss of visibility into application performance and health until the process is manually restarted.

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

Quick answers

Is CVE-2026-45686 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-45686 being exploited in the wild.
How severe is CVE-2026-45686?
High severity, with a CVSS score of 7.5, published 2 June 2026.
Which products and versions are affected?
go.opentelemetry.io/obi (Go) >= 0.7.0, < 0.9.0, SEMVER:introduced=0.7.0,fixed=0.9.0; Opentelemetry Ebpf Instrumentation >= 0.7.0, < 0.9.0.
Is there a fix for CVE-2026-45686?
Yes. go.opentelemetry.io/obi (Go): upgrade to 0.9.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-45686 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-45686?
Check whether you run go.opentelemetry.io/obi (Go), Opentelemetry Ebpf Instrumentation or Opentelemetry Otelhttp 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 0.9.0 or later
    go get go.opentelemetry.io/obi@v0.9.0

Technical details

An integer overflow exists in OBI's Memcached text protocol parser within the `memcachedCommandBytesField` function. When parsing storage commands (e.g., set, add, replace), the parser accepts extremely large `<bytes>` values via `strconv.Atoi` without upper-bound validation. When the parser subsequently adds the length of the payload delimiter (\r\n), the value overflows to a negative integer. This negative length is passed to `LargeBufferReader.Peek`, triggering a Go runtime panic due to an invalid slice bound. An attacker capable of sending Memcached traffic to an instrumented service can remotely crash the OBI process. The issue is fixed in version 0.9.0 by adding proper overflow and bounds checks.

Affected products

  • OpenTelemetry OpenTelemetry eBPF Instrumentation (OBI) >= 0.7.0, < 0.9.0

Identifiers

  • CVE-2026-45686
  • GHSA-43g7-cwr8-q3jh
  • GO-2026-5107

Timeline

  • 2026-05-11: patched: Version 0.9.0 released
  • 2026-05-12: advisory: GitHub Security Advisory published
  • 2026-06-02: disclosed: CVE-2026-45686 published to NVD

References

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