CVE-2026-45684
MEDIUMCVE-2026-45684 is a medium-severity (CVSS 4.9) CWE-126 vulnerability in go.opentelemetry.io/obi. O3 Security confirms whether CVE-2026-45684 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
OpenTelemetry eBPF Instrumentation: Log enricher writev path can overread and overwrite user buffers
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-45684.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-45684 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 0 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
go.opentelemetry.io/obiReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
OpenTelemetry eBPF Instrumentation provides eBPF instrumentation based on the OpenTelemetry standard. From version 0.7.0 to before version 0.9.0, OBI's log enricher mishandles writev buffers by reading only the first iovec entry but using the total iov_iter.count as the copy length. When log injection is enabled, a crafted multi-segment writev call can make OBI read and overwrite memory beyond the first segment. This issue has been patched in version 0.9.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | go.opentelemetry.io/obi | ≥ 0.7.0&&< 0.9.0 | 0.9.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for go.opentelemetry.io/obi. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update go.opentelemetry.io/obi to 0.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-45684 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-45684 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-45684. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-45684 in your dependencies?
O3 detects CVE-2026-45684 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.