GHSA-xrw9-r35x-x878 CVE-2025-64102 GO-2025-4085

Zitadel allows brute-forcing authentication factors

Critical Go

Severity: 0.0 / 10; Critical · CVSS 4.0
Exploit chance (EPSS): 0.37%; Chance of exploitation in the next 30 days. Higher than 30.92% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-307 Improper Restriction of Excessive Authentication Attempts
Fix: Available; 2 packages have a fixed version

Description

Summary

A vulnerability in Zitadel allowed brute-force attack on OTP, TOTP and password allowing to impersonate the attacked user.

Impact

An attacker can perform an online brute-force attack on OTP, TOTP, and passwords. While Zitadel allows preventing online brute force attacks in scenarios like TOTP, Email OTP, or passwords using a lockout mechanism. The mechanism is not enabled by default and can cause a denial of service for the corresponding user if enabled. Additionally, the mitigation strategies were not fully implemented in the more recent resource-based APIs.

Affected Versions

All versions within the following ranges, including release candidates (RCs), are affected:

4.x: 4.0.0 to 4.4.0 (including RC versions)
3.x: 3.0.0 to 3.4.2 (including RC versions)
2.x: v2.0.0 to 2.71.17

Patches

The vulnerability has been addressed in the latest releases. The patch resolves the issue by enforcing the lockout policy on all OTP, TOTP and password checks. Additionally a “tar pit” has been introduced to slow down brute-force attacks by default. Zitadel responses will be delayed by t seconds, where t increases over the number of failed attempts within a given timeframe.

4.x: Upgrade to >=4.6.0 3.x: Update to >=3.4.3 2.x: Update to >=2.71.18

Workarounds

The recommended solution is to update Zitadel to a patched version.

The problem might be mitigated by enabling the optional logout policy ("Password maximum attempts") or by implementing more strict rate limits.

Questions

If you have any questions or comments about this advisory, please email us at security@zitadel.com

Credits

This vulnerability was found by zentrust partners GmbH during a scheduled penetration test. Thank you to the analysts Martin Tschirsich, Joud Zakharia, Christopher Baumann. The full report will be made public after the complete review.

Affected versions

Go

Package	Vulnerable	Fixed in
github.com/zitadel/zitadel	`< 1.80.0-v2.20.0.20251029090735-b8db8cdf9cc8`	`1.80.0-v2.20.0.20251029090735-b8db8cdf9cc8`
github.com/zitadel/zitadel	`all versions`	No fix yet
github.com/zitadel/zitadel/v2	`< 2.71.18`	`2.71.18`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

github.com/zitadel/zitadel Go → `1.80.0-v2.20.0.20251029090735-b8db8cdf9cc8`

go

go get github.com/zitadel/zitadel@v1.80.0-v2.20.0.20251029090735-b8db8cdf9cc8 && go mod tidy

github.com/zitadel/zitadel/v2 Go → `2.71.18`

go

go get github.com/zitadel/zitadel/v2@v2.71.18 && go mod tidy

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Attack vector: Network
Attack complexity: Low
Attack requirements: Present
Privileges required: Low
User interaction: None
Confidentiality (vulnerable system): High
Integrity (vulnerable system): High
Availability (vulnerable system): High
Confidentiality (subsequent systems): None
Integrity (subsequent systems): None
Availability (subsequent systems): None

CVSS 3.1 9.8

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Weakness

CWE-307: Improper Restriction of Excessive Authentication Attempts

The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.

How to prevent it

Architecture and Design: Common protection mechanisms include: Disconnecting the user after a small number of failed attempts Implementing a timeout Locking out a targeted account Requiring a computational task on the user's part.
Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482]. Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator. [REF-45]

References

Advisories

nvd.nist.gov/vuln/detail/CVE-2025-64102

Packages

github.com/zitadel/zitadel

Timeline

Oct 29, 2025 Published
Oct 19, 2026 Last updated by the source
Nov 1, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-fgmf-7rf8-m6vf ZITADEL: Actions V1 sandbox escape: host file read via require()	High	Also affects github.com/zitadel/zitadel
GHSA-9993-rfwp-rhwf ZITADEL: MFA bypass via session reuse in Login V2	High	Also affects github.com/zitadel/zitadel
GHSA-v859-c572-qh5p ZITADEL: Improper Role Revocation on Granted Projects during Multiple Role Deletions	Medium	Also affects github.com/zitadel/zitadel
GHSA-jq8w-8q2f-ffm9 ZITADEL Users Can Self-Verify Email/Phone via API	High	Also affects github.com/zitadel/zitadel
GHSA-vrh8-c9cm-wh8v ZITADEL: Unauthorized Token Privilege Escalation in OAuth2 Token Exchange	High	Also affects github.com/zitadel/zitadel
GHSA-992q-9gwp-7r79 ZITADEL: Auto-linking by email: IdP-side email verification is not checked	Medium	Also affects github.com/zitadel/zitadel
GHSA-v77h-2w3m-94hx ZITADEL: Missing Token Expiration (`exp`) Validation in JWT IdP Provider	Medium	Also affects github.com/zitadel/zitadel
GHSA-g5h5-m4hm-xjrr ZITADEL: Missing Token Audience Validation (`aud`) in JWT IdP Provider	Medium	Also affects github.com/zitadel/zitadel

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