# CVE-2025-57770: ZITADEL user enumeration vulnerability in login UI

> An unauthenticated attacker can enumerate valid user accounts by bypassing the login UI's unknown username protection, exposing user existence.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A: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 Aug 2025
- **Updated:** 22 Aug 2025
- **Also known as:** GHSA-g9c3-xh6v-fr86

## What is CVE-2025-57770?

CVE-2025-57770 is a medium-severity vulnerability in zitadel, published on 22 Aug 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The open-source identity infrastructure software Zitadel allows administrators to disable the user self-registration. Versions 4.0.0 to 4.0.2, 3.0.0 to 3.3.6, and all versions prior to 2.71.15 are vulnerable to a username enumeration issue in the login interface. The login UI includes a security feature, Ignoring unknown usernames, that is intended to prevent username enumeration by returning a generic response for both valid and invalid usernames. This vulnerability allows an unauthenticated attacker to bypass this protection by submitting arbitrary userIDs to the select account page and distinguishing between valid and invalid accounts based on the system's response. For effective exploitation, an attacker needs to iterate through possible userIDs, but the impact can be limited by implementing rate limiting or similar measures. The issue has been patched in versions 4.0.3, 3.4.0, and 2.71.15.

Weakness: CWE-203 (Observable Discrepancy)

## Which versions are affected by CVE-2025-57770?

It affects 1 product.


Products: Zitadel Zitadel.

## How do I fix CVE-2025-57770?

No fix has been published for CVE-2025-57770 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-57770 being exploited?

There is no known exploitation of CVE-2025-57770 in the wild and no public exploit code.

## Other vulnerabilities in zitadel

- [CVE-2026-29191](https://insights.sbomify.com/CVE-2026-29191/): ZITADEL: 1-Click Account Takeover via XSS in /saml-post Endpoint (critical 9.3)
- [CVE-2025-67494](https://insights.sbomify.com/CVE-2025-67494/): ZITADEL Vulnerable to Unauthenticated Full-Read SSRF via V2 Login (critical 9.3)
- [CVE-2025-27507](https://insights.sbomify.com/CVE-2025-27507/): IDOR Vulnerabilities in ZITADEL's Admin API that Primarily Impact LDAP Configurations (critical 9.0)
- [CVE-2025-64103](https://insights.sbomify.com/CVE-2025-64103/): Zitadel Bypass Second Authentication Factor (high 8.7)
- [CVE-2025-31123](https://insights.sbomify.com/CVE-2025-31123/): Zitadel Expired JWT Keys Usable for Authorization Grants (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-57770 and fix it if it is affected.

What it is: CVE-2025-57770 is a medium-severity vulnerability in zitadel, published on 22 Aug 2025. 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-2025-57770 in the wild and no public exploit code.

Affected product: zitadel. 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-2025-57770/ (Markdown: https://insights.sbomify.com/CVE-2025-57770/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-57770
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-57770
- OSV: https://osv.dev/vulnerability/CVE-2025-57770

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-57770/
Summaries are generated and may contain mistakes; the official description above is the record.