Cyber Resilience

CVE-2026-48558

Simple-Help Simplehelp ≤ 5.5.16

CISA KEVActive ExploitationEUVD Exploited
Published
12 June 2026
Modified
07 October 2026
KEV Added
29 June 2026
Patch / advisory
View advisory
CVSS Score v4 9.5
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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 0.057 93th percentile
Risk Priority 75 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-48558 is a critical-severity Improper Verification of Cryptographic Signature (CWE-347) vulnerability in Simple-Help Simplehelp. Its CVSS base score is 9.5 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Invalid Code Signature (T1036.001); ranked in the top 7% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

The strongest mitigations our analysis identified map to SC-13 (Cryptographic Protection) and SI-7 (Software, Firmware, and Information Integrity) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A04:2025 Cryptographic Failures

EU & UK References

Vulnerability Data

SimpleHelp versions 5.5.15 and prior and 6.0 pre-release versions contain an authentication bypass vulnerability in the OIDC authentication flow. When OIDC authentication is configured, identity tokens submitted during login are accepted without verifying their cryptographic signature. In a vulnerable configuration,…

more

a remote, unauthenticated attacker can submit a forged token containing arbitrary identity claims to obtain a fully authenticated technician session. In some configurations, this may also allow bypass of multi-factor authentication. No user interaction is required.

CWE(s)
CWE-347
KEV Date Added
29 June 2026

Related Threats

MITRE ATT&CK Enterprise Techniques

T1036.001 Invalid Code Signature Stealth
Adversaries may attempt to mimic features of valid code signatures to increase the chance of deceiving a user, analyst, or tool.
attack.mitre.org →
T1195 Supply Chain Compromise Initial Access
Adversaries may manipulate products or product delivery mechanisms prior to receipt by a final consumer for the purpose of data or system compromise.
attack.mitre.org →
T1195.002 Compromise Software Supply Chain Initial Access
Adversaries may manipulate application software prior to receipt by a final consumer for the purpose of data or system compromise.
attack.mitre.org →
T1542 Pre-OS Boot Stealth
Adversaries may abuse Pre-OS Boot mechanisms as a way to establish persistence on a system.
attack.mitre.org →
T1553 Subvert Trust Controls Defense Impairment
Adversaries may undermine security controls that will either warn users of untrusted activity or prevent execution of untrusted programs.
attack.mitre.org →
T1553.002 Code Signing Defense Impairment
Adversaries may create, acquire, or steal code signing materials to sign their malware or tools.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-57727Same product: Simple-Help Simplehelpboth on KEV
CVE-2024-57726Same product: Simple-Help Simplehelpboth on KEV
CVE-2024-57728Same product: Simple-Help Simplehelpboth on KEV
CVE-2025-36727Same product: Simple-Help Simplehelp
CVE-2025-36728Same product: Simple-Help Simplehelp
CVE-2013-3900Shared CWE-347both on KEV
CVE-2020-1464Shared CWE-347both on KEV
CVE-2020-2021Shared CWE-347both on KEV
CVE-2026-5430Shared CWE-347both on KEV
CVE-2025-59718Shared CWE-347both on KEV

Affected Assets

simple-help
simplehelp
6.0 · ≤ 5.5.16

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 14 hardening rules · 5 OS baselines
Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

SC-13 Cryptographic Protection good match

Requiring cryptographic protection mechanisms forces correct signature verification to be implemented for data protection.

SI-7 Software, Firmware, and Information Integrity good match

Mandating integrity verification tools directly requires proper cryptographic signature checking to detect unauthorized changes.

SC-23 Session Authenticity partial match

Protecting session authenticity requires correct verification of cryptographic signatures or equivalent mechanisms.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

ID.RA-09 partial match
blocks

Requires assessing authenticity and integrity of acquired assets, which commonly relies on signature verification but is limited to pre-acquisition.

PR.DS-01 partial match
blocks

Digital signatures are explicitly cited to protect integrity of data-at-rest, so proper verification directly mitigates the weakness.

PR.DS-02 partial match
blocks

Digital signatures are explicitly cited to protect integrity of data-in-transit, so proper verification directly mitigates the weakness.

PR.PS-06 partial match
blocks

Secure SDLC practices include code signing and signature verification requirements, addressing the weakness during development.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.8.10 Information deletion partial match
removes

References