CVE-2026-45783
HIGHCVE-2026-45783 is a high-severity (CVSS 7.5) vulnerability in @libp2p/kad-dht. O3 Security confirms whether CVE-2026-45783 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
libp2p: Unvalidated PUT_VALUE records allow unbounded disk exhaustion on DHT server nodes
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
@libp2p/kad-dhtnpmDescription
libp2p is a JavaScript Implementation of libp2p networking stack. Prior to version 16.2.6, an unauthenticated remote peer can exhaust the disk storage of any @libp2p/kad-dht node running in server mode by sending an unbounded stream of PUT_VALUE messages whose keys bypass all content validation. No credentials, no prior relationship, and no protocol deviation beyond a crafted key are required. The victim node's datastore fills until the host disk is exhausted, making the node unavailable. This issue has been patched in version 16.2.6.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @libp2p/kad-dht | all versions | 16.2.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @libp2p/kad-dht. 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 @libp2p/kad-dht to 16.2.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-45783 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-2026-45783 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-2026-45783. 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-2026-45783 in your dependencies?
O3 detects CVE-2026-45783 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.