Cyber Resilience

CVE-2026-4639

High

Published: 24 March 2026

Published
24 March 2026
Modified
15 April 2026
KEV Added
Patch
CVSS Score v4 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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 0.0030 21.4th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-4639 is a high-severity Incorrect Authorization (CWE-863) vulnerability in Gss Vitalsesp. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 21.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 AC-3 (Access Enforcement) and AC-6 (Least Privilege).

Deeper analysis

CVE-2026-4639 is an Incorrect Authorization vulnerability (CWE-863) in Vitals ESP, a product developed by Galaxy Software Services. Published on 2026-03-24, it enables authenticated remote attackers to perform certain administrative functions, leading to privilege escalation. The vulnerability carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), indicating high severity due to its network accessibility, low attack complexity, and significant impacts on confidentiality, integrity, and availability.

An attacker with low-level authenticated access over the network can exploit this flaw without user interaction. Successful exploitation allows the attacker to execute administrative actions beyond their intended privileges, potentially compromising the entire system by gaining unauthorized control over sensitive operations.

TWCERT advisories provide further details on the vulnerability, including mitigation recommendations, accessible at https://www.twcert.org.tw/en/cp-139-10795-25784-2.html and https://www.twcert.org.tw/tw/cp-132-10794-704a2-1.html. Security practitioners should consult these for specific patch information or workarounds from Galaxy Software Services.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

Vitals ESP developed by Galaxy Software Services has a Incorrect Authorization vulnerability, allowing authenticated remote attackers to perform certain administrative functions, thereby escalating privileges.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
Why these techniques?

Incorrect authorization flaw enables low-privileged authenticated remote attackers to escalate to administrative privileges through exploitation.

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

CVEs Like This One

CVE-2026-4640Same product: Gss Vitalsesp
CVE-2025-64421Shared CWE-863
CVE-2026-41404Shared CWE-863
CVE-2024-44305Shared CWE-863
CVE-2026-41344Shared CWE-863
CVE-2025-27822Shared CWE-863
CVE-2026-47101Shared CWE-863
CVE-2025-0359Shared CWE-863
CVE-2025-14866Shared CWE-863
CVE-2024-13282Shared CWE-863

Affected Assets

gss
vitalsesp
≤ 6.3

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Enforces approved authorizations for logical access, directly preventing authenticated low-privilege attackers from performing unauthorized administrative functions.

prevent

Employs least privilege to ensure only authorized users can execute administrative actions, mitigating privilege escalation risks.

prevent

Identifies and corrects the specific incorrect authorization flaw through timely flaw remediation and patching.

References