CVE-2026-48504 is a medium-severity (CVSS 5.3) CWE-770 vulnerability in opentelemetry_sdk. O3 Security confirms whether CVE-2026-48504 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
OpenTelemetry Rust: Unbounded memory allocation in W3C Baggage propagation
Real-World Exposure
opentelemetry_sdkReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
OpenTelemetry Rust is the Rust OpenTelemetry implementation. In 0.32.0 and earlier, BaggagePropagator::extract_with_context in opentelemetry_sdk did not enforce W3C Baggage size limits before parsing an inbound baggage header, so a large attacker-controlled header could cause unnecessary CPU work and short-lived heap allocations while parsing entries later discarded by the SDK's baggage storage limits. Services that accept untrusted inbound propagation headers may experience increased per-request resource usage when processing oversized baggage headers. This issue is fixed in version 0.32.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | opentelemetry_sdk | all versions | 0.32.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for opentelemetry_sdk. 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 opentelemetry_sdk to 0.32.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-48504 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-2026-48504 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-2026-48504. 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-2026-48504 in your dependencies?
O3 detects CVE-2026-48504 across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.