Critical 9.3Published Oct 6, 2025

CVE-2025-61778Akka.NET is a .NET port of the Akka project from the Scala / Java community.

Updated under an hour ago (2026-10-19 09:10 UTC)

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Exploited in the last 30 days

Akka.NET is a .NET port of the Akka project from the Scala / Java community. 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. Those who run Akka.NET inside a private network that they fully control or who were never using TLS in the first place are now affected by the bug. However, those who use TLS to secure their networks must upgrade to Akka.NET V1.5.52 or later. One patch 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. The second patch, a critical fix, enforces mutual TLS (mTLS) by default, so both parties must be keyed using the same certificate. As a workaround, avoid exposing the application publicly to avoid the vulnerability having a practical impact on one's application. However, upgrading to version 1.5.52 is still recommended by the maintainers.

CVSS: 9.3 CRITICAL (v4.0, NVD)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Weakness (CWE): CWE-290, CWE-295, CWE-306
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Not given
NVD analysis: Deferred
Record last updated: Oct 9, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

No affected products are listed yet.

References

https://getakka.net/articles/remoting/security.html
https://github.com/akkadotnet/akka.net/pull/7847
https://github.com/akkadotnet/akka.net/pull/7851
https://github.com/akkadotnet/akka.net/releases/tag/1.5.52
https://github.com/akkadotnet/akka.net/security/advisories/GHSA-jhpv-4q4f-43g5

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.