# CVE-2026-5749: Inadequate access control vulnerability in Fullstep

> Unauthenticated attackers can obtain valid JWT tokens via inadequate registration access control, allowing unauthorized access to protected API resources.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/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:** 22 Apr 2026
- **Updated:** 22 Apr 2026
- **Also known as:** GHSA-c4hv-pjjq-493x

## What is CVE-2026-5749?

CVE-2026-5749 is a high-severity authentication bypass vulnerability in Fullstep, published on 22 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Inadequate access control in the registration process in Fullstep V5, which could allow unauthenticated users to obtain a valid JWT token with which to interact with authenticated API resources. Successful exploitation of this vulnerability could allow an unauthenticated attacker to compromise the confidentiality of the affected resource, provided they have a valid token with which to interact with the API.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2026-5749?


## How do I fix CVE-2026-5749?

No fix has been published for CVE-2026-5749 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-5749 being exploited?

There is no known exploitation of CVE-2026-5749 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5749 and fix it if it is affected.

What it is: CVE-2026-5749 is a high-severity authentication bypass vulnerability in Fullstep, published on 22 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-5749 in the wild and no public exploit code.

Affected product: Fullstep. 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-2026-5749/ (Markdown: https://insights.sbomify.com/CVE-2026-5749/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5749
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5749
- OSV: https://osv.dev/vulnerability/CVE-2026-5749

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-5749/
Summaries are generated and may contain mistakes; the official description above is the record.