Auth bypass in Code100x
CVE-2026-8890
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.
Vulnerability class: IDOR (Insecure Direct Object Reference)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N.
EPSS exploit prediction
EPSS: 0.006 (45.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 45.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.006 · change: +0.001
Affected products
- Code100x — versions 0
Weakness classification (CWE)
References
- github.com/code100x/cms/issues/1924 (issue-tracking, technical-description)
- github.com/code100x/cms/pull/1927 (issue-tracking)
- github.com/code100x/cms/pull/1927/changes/90b489ee7c63c301107d6374d4b3f2b8e4060… (issue-tracking)
- github.com/code100x/cms/pull/1927/changes/88c6c5e94e23da101235c4c7e9c7591ac1016… (issue-tracking)
- www.vulncheck.com/advisories/code100x-mobile-api-authentication-bypass-via-head… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-8890?
- CVE-2026-8890 is a high-severity vulnerability in Code100x, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 8.2/10. Published 2026-05-26.
- How severe is CVE-2026-8890?
- High severity. CVSS v3 base score is 8.2 out of 10.