Cyber Resilience

CVE-2026-53871

HighPublic PoC

Published: 17 June 2026

Published
17 June 2026
Modified
18 June 2026
KEV Added
—
Patch
—
CVSS Score v4 8.6 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/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 0.0037 28.5th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-53871 is a high-severity Reliance on Cookies without Validation and Integrity Checking (CWE-565) vulnerability. Its CVSS base score is 8.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 28.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

A08:2025 Software or Data Integrity Failures

EU & UK References

Vulnerability details

Hermes WebUI before 0.51.368 contains an authorization bypass vulnerability in the get_profile_cookie() function that accepts unauthenticated profile names from the hermes_profile cookie. An authenticated attacker can forge the hermes_profile cookie value to bypass profile-scoped authorization checks and access sessions, files,…

more

and resources across different profiles.

CWE(s)
CWE-565

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 →
T1550.004 Web Session Cookie Lateral Movement
Adversaries can use stolen session cookies to authenticate to web applications and services.
attack.mitre.org →
Why these techniques?

Authorization bypass via forged web cookie in public-facing WebUI directly enables T1190 exploitation and T1550.004 alternate auth material abuse for cross-profile access.

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

Affected Assets

Mitigating Controls

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

References