CVE-2022-46149
MEDIUMCap'n Proto vulnerable to out-of-bounds read due to logic error handling list-of-list.
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.
Blast Radius
capnp🦀capnp🦀capnpReal-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
Cap'n Proto is a data interchange format and remote procedure call (RPC) system. Cap'n Proro prior to versions 0.7.1, 0.8.1, 0.9.2, and 0.10.3, as well as versions of Cap'n Proto's Rust implementation prior to 0.13.7, 0.14.11, and 0.15.2 are vulnerable to out-of-bounds read due to logic error handling list-of-list. This issue may lead someone to remotely segfault a peer by sending it a malicious message, if the victim performs certain actions on a list-of-pointer type. Exfiltration of memory is possible if the victim performs additional certain actions on a list-of-pointer type. To be vulnerable, an application must perform a specific sequence of actions, described in the GitHub Security Advisory. The bug is present in inlined code, therefore the fix will require rebuilding dependent applications. Cap'n Proto has C++ fixes available in versions 0.7.1, 0.8.1, 0.9.2, and 0.10.3. The capnp Rust crate has fixes available in versions 0.13.7, 0.14.11, and 0.15.2.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | capnp | ≥ 0.15.0&&< 0.15.2 | 0.15.2 |
| 🦀crates.io | capnp | ≥ 0.14.0&&< 0.14.11 | 0.14.11 |
| 🦀crates.io | capnp | all versions | 0.13.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for capnp. 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 capnp to 0.15.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-46149 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-2022-46149 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-2022-46149. 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-2022-46149 in your dependencies?
O3 detects CVE-2022-46149 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.