How severe is CVE-2025-61778?

No CVSS score has been assigned to CVE-2025-61778 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2025-61778?

CVE-2025-61778 affects the following packages: Akka.Remote (NuGet), Akka.Cluster (NuGet). Ecosystems affected: NuGet.

How do I fix CVE-2025-61778?

Update Akka.Remote to 1.5.52 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-61778 is resolved across your whole dependency graph.

How do I detect CVE-2025-61778 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Akka.Remote, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2025-61778 if there is no patch (or I can't update yet)?

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 does O3 Security protect against CVE-2025-61778?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-61778 can be triaged on real exposure rather than presence alone.

Is CVE-2025-61778 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-61778 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2025-61778?

CVE-2025-61778 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 24th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2025-61778?

CVE-2025-61778 is classified as CWE-290 (CWE-290), CWE-295 (CWE-295), Missing Authentication (CWE-306). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2025-61778 published, and has it been updated?

CVE-2025-61778 was published on October 6, 2025 and was last updated on August 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

.NET NuGet

Not in CISA KEV

CVE-2025-61778 — Akka.Remote

Fix: akkadotnet/akka.net#7847

CVE-2025-61778 is a CWE-290 vulnerability in Akka.Remote. A fix is available for Akka.Remote — see the affected versions and patch details below.

Akka.Remote TLS did not properly implement certificate-based authentication

Also known asGHSA-jhpv-4q4f-43g5

Published

Oct 6, 2025

Updated

Aug 12, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Sep 19, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2025-61778.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs24th percentile — riskier than 24% of all scored CVEsHighest risk

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.

Real-World Exposure

2 pkgs affected

.NETAkka.Remote.NETAkka.Cluster

Real-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

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.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`Akka.Remote`	≥ 1.2.0&&< 1.5.52	1.5.52`dotnet add package Akka.Remote --version 1.5.52`
.NETNuGet	`Akka.Cluster`	≥ 1.2.0&&< 1.5.52	1.5.52`dotnet add package Akka.Cluster --version 1.5.52`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Akka.Remote, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Akka.Remote to 1.5.52 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-61778 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-61778 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2025-61778. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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 authenticatio

O3 Security · Impact-Aware SCA

Is CVE-2025-61778 in your dependencies?

O3 Security finds CVE-2025-61778 across NuGet dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works