CVE-2026-48558
Exploitation confirmed. First attested on 2026-06-29 by CISA-ADP, CISA KEV, GCVE · kevintel.
- Published2026-06-12
- Fixed in5.5.16
- WeaknessCWE-347
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
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.
Timeline
dates in UTCObserved activity
isMalicious corpus · updated 2026-10-23 18:48 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-48558?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-48558?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 5.5 | < 5.5.16 | 5.5.16 | NVD |
| 6.0 | = 6.0 | no fix published | NVD |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
- Update Simple-help simplehelp to 5.5.16
- CISA’s required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.due 2026-07-02
Advisories and patches
- simple-help.comRelease Notes
- simple-help.comPatch · Vendor Advisory
Detection
read 2026-10-23 19:25 UTC- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
CISA Known Exploited Vulnerability
- Date Added
- 2026-06-29
- Patch Due Date
- 2026-07-02
- Ransomware Use
- Unknown
- Required Action
- Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Sources
- NVDCVE recordread 2026-10-23
- CISA KEVKEV entry2026-06-29
- GCVEexploitation2026-06-29
- CISA-ADPSSVC decisionactive2026-06-30
- OpenCVESSVC decisionactive—
- CNACVSS 4.09.5read 2026-10-23
- CNACVSS 3.110read 2026-10-23
- CNAweakness (CWE)CWE-347read 2026-10-23
- FIRST EPSSEPSS score5.7 %2026-10-22
- PoC-in-GitHubproof of concept1read 2026-10-23
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- CVSS 4.0 vector
- 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
- Published
- 2026-06-12
- Last Modified
- 2026-10-07
- NVD status
- Analyzed
Frequently asked questions
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Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.