Cyber Resilience

CVE-2026-48558

CriticalCISA KEVActive ExploitationUpdated

Published: 12 June 2026

Published
12 June 2026
Modified
30 June 2026
KEV Added
29 June 2026
Patch
—
CVSS Score v4 9.5 CVSS: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 0.0116 63.3th percentile
Risk Priority 100 floored blend · peak EPSS

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, ranked in the top 36.7% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

The strongest mitigations our analysis identified are NIST 800-53 IA-13 (Identity Providers and Authorization Servers) and IA-2 (Identification and Authentication (Organizational Users)).

OWASP Top 10 for Web (2025)

A04:2025 Cryptographic Failures

EU & UK References

Vulnerability details

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 TechniquesAI

Insufficient information to map techniques.
Confidence: LOW · MITRE ATT&CK Enterprise v19.0

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-2025-36728Same product: Simple-Help Simplehelp
CVE-2025-36727Same product: Simple-Help Simplehelp
CVE-2013-3900Shared CWE-347both on KEV
CVE-2020-1464Shared CWE-347both on KEV
CVE-2025-59718Shared CWE-347both on KEV
CVE-2025-47827Shared CWE-347both on KEV
CVE-2020-2021Shared CWE-347both on KEV

Affected Assets

simple-help
simplehelp
6.0 · ≤ 5.5.16

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

IA-13 Identity Providers and Authorization Servers good match
prevent

Directly requires proper validation of tokens and assertions from identity providers, which the CVE bypasses by accepting unsigned OIDC tokens.

IA-2 Identification and Authentication (Organizational Users) good match
prevent

Mandates cryptographic verification of user identity tokens before granting authenticated sessions, directly blocking the forged-token attack.

SC-23 Session Authenticity partial match
prevent

Requires mechanisms to ensure session authenticity, which fails when OIDC tokens lack signature validation and allow impersonation.

Hardening callouts derived

Configuration rules from DISA STIG baselines that reduce the attack surface for weaknesses of the type cited by this CVE. Derived transitively via CVE→CWE→STIG over `controls_xwalks` (authoritative rows only).

Oracle Linux 8 (2 rules)
  • V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. via CWE-347
  • V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. via CWE-347
Oracle Linux 9 (2 rules)
  • V-271523 OL 9 must check the GPG signature of locally installed software packages before installation. via CWE-347
  • V-271525 OL 9 must have GPG signature verification enabled for all software repositories. via CWE-347
RHEL 7 (2 rules)
  • V-204447 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. via CWE-347
  • V-204448 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. via CWE-347
RHEL 8 (1 rule)
  • V-230264 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. via CWE-347
RHEL 9 (1 rule)
  • V-257822 RHEL 9 must have GPG signature verification enabled for all software repositories. via CWE-347

References