GHSA-jhpv-4q4f-43g5
Akka.Remote TLS did not properly implement certificate-based authentication
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
Akka.Remote.NETAkka.ClusterReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.
Description
Impact
This is a critical network security vulnerability for Akka.Remote users who have SSL / TLS enabled on their Akka.Remote connections and were expecting certificate-based authentication to be enforced on all peers attempting to join the network.
In all versions of Akka.Remote from v1.2.0 to v1.5.51, TLS could be enabled via our akka.remote.dot-netty.tcp transport and this would correctly enforce private key validation on the server-side of inbound connections. Akka.Remote, however, never asked the outbound-connecting client to present ITS certificate - therefore it's possible for untrusted parties to connect to a private key'd Akka.NET cluster and begin communicating with it without any certificate.
The issue here is that for certificate-based authentication to work properly, ensuring that all members of the Akka.Remote network are secured with the same private key, Akka.Remote needed to implement mutual TLS. This was not the case before Akka.NET v1.5.52.
If you are running Akka.NET inside a private network you fully control or you were never using TLS in the first place, then this bug has no impact on you. However: if you are using TLS to secure your network YOU MUST upgrade to Akka.NET V1.5.52 or later.
Patches
https://github.com/akkadotnet/akka.net/pull/7847 - forces "fail fast" semantics if TLS is enabled but the private key is missing or invalid. Previous versions would only check that once connection attempts occurred. https://github.com/akkadotnet/akka.net/pull/7851 - critical fix: enforces mutual TLS (mTLS) by default, so both parties must be keyed using the same certificate. This fulfills the original security
These updates have been shipped into Akka.NET v1.5.52: https://github.com/akkadotnet/akka.net/releases/tag/1.5.52
Workarounds
If your application isn't exposed publicly, then CVE-2025-61778 has no practical impact on your application. That being said: upgrading to Akka.NET v1.5.52 or later is a good idea.
References
Please view our latest network security documentation here: https://getakka.net/articles/remoting/security.html
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Akka.Remote | ≥ 1.2.0&&< 1.5.52 | 1.5.52 |
| .NETNuGet | Akka.Cluster | ≥ 1.2.0&&< 1.5.52 | 1.5.52 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Akka.Remote. 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 Akka.Remote to 1.5.52 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-jhpv-4q4f-43g5 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 GHSA-jhpv-4q4f-43g5 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 GHSA-jhpv-4q4f-43g5. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-jhpv-4q4f-43g5 in your dependencies?
O3 detects GHSA-jhpv-4q4f-43g5 across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.