CVE-2026-61554: emp3r0r has an unauthenticated HTTP Polling DoS
Vulnerability summary
CVE-2026-61554 is a high (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in jm33-m0 emp3r0r. EPSS estimates a 0.71% chance of exploitation in the next 30 days, higher than 53.5% of scored vulnerabilities.
Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 04-11-2026)
Source freshness unavailable
How is this decided?Timeline
- 15-09-2026PublishedVulnerability first disclosed.
- 16-09-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · GoEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.71%
Chance of exploitation in the next 30 days
Percentile
54%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.71% on 05-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Github.com/jm33-m0/emp3r0r1 product
- core< 0.0.0-20260531142011-aed3d81641ab
Jm33-m01 product
- emp3r0r< 4.2.5
2 vendors · 2 products
References
3 links- github.com/jm33-m0/emp3r0rPACKAGE