emp3r0r has an unauthenticated HTTP Polling DoS

Answer in brief

CVE-2026-61554 records a High severity (CVSS 7.5) vulnerability in emp3r0r has an unauthenticated HTTP Polling DoS. The current sources do not mark it as known exploited. The current feed maps jm33-m0/emp3r0r (generic), github.com/jm33-m0/emp3r0r/core (go). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 15, 2026Updated Sep 15, 2026Source checked Sep 15, 2026First seen by HOL Sep 15, 2026Material review Sep 15, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.5
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps jm33-m0/emp3r0r (generic), github.com/jm33-m0/emp3r0r/core (go). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
jm33-m0/emp3r0rgeneric	< 4.2.5	Not reported
github.com/jm33-m0/emp3r0r/corego	<0.0.0-20260531142011-aed3d81641ab	0.0.0-20260531142011-aed3d81641ab

Recommended response

Check inventory. Check lockfiles and deployed manifests for jm33-m0/emp3r0r, github.com/jm33-m0/emp3r0r/core.
Review the reported fix. Update github.com/jm33-m0/emp3r0r/core to 0.0.0-20260531142011-aed3d81641ab if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 15, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.