CVE Catalog

CVE-2026-61554

HighCVSS 7.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Elevated risk
0.71%

52th percentile - higher than 52% of all known CVEs

Summary

emp3r0r is a C2 designed by Linux users for Linux environments. Prior to version 4.2.5, the http_poll C2 transport accepts attacker-controlled HTTP polling sessions before CBOR MsgAuth authentication is completed. A remote unauthenticated attacker can create arbitrary polling sessions and send request bodies that are forwarded into the C2 dispatch path. This can consume server resources and trigger pre-auth C2 processing. Version 4.2.5 patches the issue.

Risk Assessment

The risk includes server resource exhaustion and potential disruption of C2 operations, which could affect availability and operational integrity.

Recommendation

Update emp3r0r to version 4.2.5 or later and implement authentication before accepting polling sessions.

Related vulnerabilities

Original NVD description (English source)

emp3r0r is a C2 designed by Linux users for Linux environments. Prior to version 4.2.5, the `http_poll` C2 transport accepts attacker-controlled HTTP polling sessions before CBOR `MsgAuth` authentication is completed. A remote unauthenticated attacker can create arbitrary polling sessions and send request bodies that are forwarded into the C2 dispatch path. This can consume server resources and trigger pre-auth C2 processing. Version 4.2.5 patches the issue.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS