Cyber Resilience

CVE-2026-25555

CriticalPublic PoCUpdated

Published: 08 June 2026

Published
08 June 2026
Modified
17 June 2026
KEV Added
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Patch
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CVSS Score v4 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0151 71.3th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-25555 is a critical-severity Authentication Bypass by Primary Weakness (CWE-305) vulnerability in Hackernoon (inferred from references). Its CVSS base score is 9.3 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 28.7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

A07:2025 Authentication Failures

EU & UK References

Vulnerability details

OpenBullet2 through version 0.3.2 contains an authentication bypass vulnerability in the API key authentication middleware that allows unauthenticated attackers to gain admin access by supplying an empty X-Api-Key header value. Attackers can exploit the middleware's comparison of the supplied header…

more

against an empty AdminApiKey default string to access the admin console and all API endpoints without valid credentials.

CWE(s)
CWE-305

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Why these techniques?

Auth bypass in API middleware directly enables remote exploitation of a public-facing application to gain unauthorized admin access.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

Affected Assets

Hackernoon
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inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References