CVE-2026-48558
SimpleHelp Authentication Bypass via Missing OIDC JWT Signature Verification
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
Description
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, 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.
Official description from the CVE record, published by VulnCheck. Copyright © 1999-2026 The MITRE Corporation. See /security/cve/legal for the CVE license. View the record on cve.org
Key data
CVSS 4.0 Critical 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
Attack vector: Network
The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity: Low
No measurable action is needed to get around the system's built-in security controls. The attack is repeatable.
Attack requirements: Present
The attack depends on certain deployment or execution conditions being present.
Privileges required: None
No account or privileges are needed.
User interaction: None
No action from any user is needed.
Vulnerable system: confidentiality: High
Serious or total effect on the secrecy of data.
Vulnerable system: integrity: High
Serious or total effect on the trustworthiness of data.
Vulnerable system: availability: High
Serious or total effect on availability.
Subsequent systems: confidentiality: High
Serious or total effect on other systems' data secrecy.
Subsequent systems: integrity: High
Serious or total effect on other systems' data trustworthiness.
Subsequent systems: availability: High
Serious or total effect on other systems' availability.
| Metric | Value | What it means |
|---|---|---|
| Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity | Low | No measurable action is needed to get around the system's built-in security controls. The attack is repeatable. |
| Attack requirements | Present | The attack depends on certain deployment or execution conditions being present. |
| Privileges required | None | No account or privileges are needed. |
| User interaction | None | No action from any user is needed. |
| Vulnerable system: confidentiality | High | Serious or total effect on the secrecy of data. |
| Vulnerable system: integrity | High | Serious or total effect on the trustworthiness of data. |
| Vulnerable system: availability | High | Serious or total effect on availability. |
| Subsequent systems: confidentiality | High | Serious or total effect on other systems' data secrecy. |
| Subsequent systems: integrity | High | Serious or total effect on other systems' data trustworthiness. |
| Subsequent systems: availability | High | Serious or total effect on other systems' availability. |
CVSS 3.1 Critical 10.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Attack vector: Network
The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity: Low
No special conditions are needed. The attack can be repeated at will.
Privileges required: None
No account or privileges are needed.
User interaction: None
No action from any user is needed.
Scope: Changed
The impact can reach other components beyond the vulnerable one.
Confidentiality impact: High
Serious or total effect on the secrecy of data.
Integrity impact: High
Serious or total effect on the trustworthiness of data.
Availability impact: High
Serious or total effect on availability.
| Metric | Value | What it means |
|---|---|---|
| Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity | Low | No special conditions are needed. The attack can be repeated at will. |
| Privileges required | None | No account or privileges are needed. |
| User interaction | None | No action from any user is needed. |
| Scope | Changed | The impact can reach other components beyond the vulnerable one. |
| Confidentiality impact | High | Serious or total effect on the secrecy of data. |
| Integrity impact | High | Serious or total effect on the trustworthiness of data. |
| Availability impact | High | Serious or total effect on availability. |
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EPSS
- Score
- 0.80251 (80.3% probability)
- Percentile
- 99.6%
- Scores of
- Nov 10, 2026
- Model
- v2026.06.15
CISA Known Exploited Vulnerabilities
- Name in the catalog
- SimpleHelp Authentication Bypass Vulnerability
- Added to the catalog
- Jun 29, 2026
- Federal due date
- Jul 2, 2026
CISA assessment as of Jun 30, 2026
- Exploitation
- Recorded by CISA as active
- Automatable
- yes
- Technical impact
- total
Weakness (CWE)
- CWE-347Improper Verification of Cryptographic Signature
Affected products
SimpleHelp
- affected: 5.5.0 up to before 5.5.16
- affected: 6.0 up to before 6.0 RC2
References
- horizon3.ai/attack-research/disclosures/cve-2026-48558-simp…technical-descriptionexploit
- simple-help.com/security/simplehelp-security-update-2026-05vendor-advisory
- simple-help.com/release-newsrelease-notes
Timeline
- ID reserved
- Record published
- Added to CISA KEV
- Record last updated
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About CubePath
Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:50 UTC. Sources and licenses