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

> Attackers can bypass authentication in the code100x Mobile API by spoofing headers to access unauthorized user and administrator course data.

- **Severity:** High 8.8 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 26 May 2026
- **Updated:** 23 Jun 2026
- **Also known as:** GHSA-qggg-4j5m-mx55

## What is CVE-2026-8890?

CVE-2026-8890 is a high-severity authentication bypass vulnerability in code100x, published on 26 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### 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.

Weakness: CWE-639 (Authorization Bypass Through User-Controlled Key)

## Which versions are affected by CVE-2026-8890?


## How do I fix CVE-2026-8890?

No fix has been published for CVE-2026-8890 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-8890 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-8890 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-8890 and fix it if it is affected.

What it is: CVE-2026-8890 is a high-severity authentication bypass vulnerability in code100x, published on 26 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-8890 exists.

Affected product: code100x. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-8890/ (Markdown: https://insights.sbomify.com/CVE-2026-8890/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-8890
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-8890
- OSV: https://osv.dev/vulnerability/CVE-2026-8890

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-8890/
Summaries are generated and may contain mistakes; the official description above is the record.