CVE-2026-61554

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.7%, top 49% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.5Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
7.5
EG Score
7.5(medium)
EG Risk
65(Attend)
EG Risk 65/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
51%
KEV
Not listed

Published

September 15, 2026

Last Modified

September 16, 2026

Advisory Details (2)

Auto-updated Sep 15, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_release.
github_release Patch Available

v4.2.5

Patch available: jm33-m0/emp3r0r v4.2.5

https://github.com/jm33-m0/emp3r0r/releases/tag/v4.2.5
github Patch Available🟡 PoC Available

Unauthenticated HTTP Polling DoS · Advisory · jm33-m0/emp3r0r · GitHub

https://github.com/jm33-m0/emp3r0r/security/advisories/GHSA-4595-rvpx-4q34

Vendor Advisories for CVE-2026-61554(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
github.com/jm33-m0/emp3r0r/core—0.0.0-20260531142011-aed3d81641ab—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 10× in last 7d / 17× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-24 18:06 UTCEG score recompute
  2. 2026-09-24 05:01 UTCEG score recompute
  3. 2026-09-23 17:54 UTCEPSS rescore
  4. 2026-09-23 03:40 UTCEG score recompute
  5. 2026-09-22 02:17 UTCEG score recompute
  6. 2026-09-21 00:54 UTCEG score recompute
  7. 2026-09-20 20:16 UTCEPSS rescore
  8. 2026-09-19 23:32 UTCEG score recompute
  9. 2026-09-18 22:09 UTCEG score recompute
  10. 2026-09-18 19:28 UTCEPSS rescore
  11. 2026-09-17 20:47 UTCEG score recompute
  12. 2026-09-16 19:25 UTCEG score recompute
  13. 2026-09-16 18:26 UTCEG score recompute
  14. 2026-09-16 14:08 UTCEPSS rescore
  15. 2026-09-15 21:18 UTCEG score recompute
  16. 2026-09-15 20:53 UTCEG score recompute
  17. 2026-09-15 20:52 UTCMITRE cvelistV5first tracked

Related CVEs(same product + same CWE)

Same product

1 shown

Go:github.com/jm33-m0/emp3r0r/core

Frequently asked(5)

What is CVE-2026-61554?
CVE-2026-61554 is a high vulnerability published on September 15, 2026. 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…
When was CVE-2026-61554 disclosed?
CVE-2026-61554 was first published in the National Vulnerability Database on September 15, 2026, with the most recent update on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-61554 actively exploited?
CVE-2026-61554 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 48.6% of all scored CVEs.
What is the CVSS score of CVE-2026-61554?
CVE-2026-61554 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-61554?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-61554, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-61554

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