CVE-2026-8890Public exploitNetwork attack vector

Unauthenticated course-data access via spoofed identity header

Published May 26, 2026 · Updated May 26, 2026

Authentication bypass in the Mobile API of 100xDevs CMS allows remote attackers to access other users' course data through spoofed headers. The withMobileAuth middleware treats any present Auth-Key as sufficient and forwards a client-controlled g header that the mobile courses route parses as trusted identity JSON. No credentials are required, but the request must supply an enrolled user identifier and a course identifier; successful exploitation exposes that identity's course data.

CVSS severity8.8
High
EPSS probability0.49%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in the Mobile API of 100xDevs CMS allows remote attackers to access other users' course data through spoofed headers. The withMobileAuth middleware treats any present Auth-Key as sufficient and forwards a client-controlled g header that the mobile courses route parses as trusted identity JSON. No credentials are required, but the request must supply an enrolled user identifier and a course identifier; successful exploitation exposes that identity's course data.

The record

CVE
CVE-2026-8890
Published
May 26, 2026
Updated
May 26, 2026
Vendor
100xDevs
Product
100xDevs CMS
Classifications
CWE-639, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 26, 2026CVE publishedPublication date reported by the CVE source.
  2. May 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <88c6c5e94e23da101235c4c7e9c7591ac1016549
  2. Affected versionversion=0 <90b489ee7c63c301107d6374d4b3f2b8e4060fe5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

100xDevs · 100xDevs CMSversion=0 <88c6c5e94e23da101235c4c7e9c7591ac1016549; version=0 <90b489ee7c63c301107d6374d4b3f2b8e4060fe5

Published CVSS scores

8.2VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
8.8VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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