Vulnerability · Published May 26, 2026 · Assigned by VulnCheck

CVE-2026-8890code100x Mobile API Authentication Bypass via Header Spoofing

High 8.2

In plain English

A high-severity authorization bypass via user-controlled key in code100x from code100x. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities).

Severity (CVSS 3.1)8.2High

Exploit odds (30 days)0.5%top 57.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

code100x contains an authentication bypass vulnerability in the Mobile API that allows unauthenticated attackers to impersonate arbitrary users by supplying a crafted JSON payload in the 'g' HTTP header. The middleware in middleware.ts skips identity header generation when an Auth-Key header is present without validating its value, allowing attackers to inject a spoofed user identity header that the downstream route handler in the mobile courses endpoint accepts as trusted, granting unauthorized access to course data belonging to any enrolled user or administrator.

Affected products (as reported)

Vendor	Product	Versions
code100x	code100x	0 – before 90b489ee7c63c301107d6374d4b3f2b8e4060fe50 – before 88c6c5e94e23da101235c4c7e9c7591ac1016549

Weakness: CWE-639 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

References

https://github.com/code100x/cms/issues/1924 issue-tracking
https://github.com/code100x/cms/pull/1927 issue-tracking
https://github.com/code100x/cms/pull/1927/changes/90b489ee7c63c301107d6374d4b3f2b8e4060fe5 issue-tracking
https://github.com/code100x/cms/pull/1927/changes/88c6c5e94e23da101235c4c7e9c7591ac1016549 issue-tracking
https://www.vulncheck.com/advisories/code100x-mobile-api-authentication-bypass-via-header-spoofing third-party-advisory