GHSA-v859-c572-qh5p CVE-2026-76081 GO-2026-6473

ZITADEL: Improper Role Revocation on Granted Projects during Multiple Role Deletions

Medium Go

Severity: 5.5 / 10; Medium · CVSS 3.1
Exploit chance (EPSS): 0.40%; Chance of exploitation in the next 30 days. Higher than 33.95% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-193 Off-by-one Error
Fix: 4.16.0; Upgrade github.com/zitadel/zitadel to this version or later

Description

Summary

A bug in how ZITADEL updates permissions when multiple project roles are deleted at the same time can cause some user permissions to be missed. This issue specifically affects User Grants on Granted Projects (projects shared between different organizations), potentially allowing users to keep access rights that were supposed to be completely removed.

Impact

When an organization shares a project with another organization (a Project Grant), administrators can assign specific roles to users via a User Grant. If multiple roles are deleted from that project at the same time, a background process runs to strip those roles from the assigned users.

Because of an error in how ZITADEL loops through a user's list of roles during this specific cross-organization cleanup, deleting two or more roles at once might cause the system to accidentally skip over some of them.

Scope Note: This vulnerability only affects User Grants on Granted Projects. Direct project roles and global organization roles are not impacted.

The risk depends entirely on what the skipped role allowed the user to do—if it was an administrative or high-privilege role, the user could potentially retain those elevated permissions within that granted project even after the role was officially deleted.

Affected Versions

4.x: 4.0.0 through 4.15.3 (including RC versions)
3.x: 3.0.0 through 3.4.12 (including RC versions)

Note: The 3.x release channel has reached End-of-Life (EOL) for security updates and will not receive a backported patch.

Patches & Resolution

This issue has been fully resolved in the latest releases.

The update fixes the role-removal logic to ensure no roles are skipped. Furthermore, this patch includes an automatic database migration. When you update, the system will automatically scan your database, find any user permissions on granted projects that may have been accidentally left behind by this bug, and correct them.

4.x: Upgrade to $\ge$4.16.0
3.x: Update to $\ge$4.16.0 (or check out workarounds)

Workarounds

There are no configuration workarounds. Upgrading to a patched version is the recommended solution and only way to trigger the automatic cleanup migration. If you cannot upgrade immediately, we recommend manually reviewing user permissions specifically for your Granted Projects where multiple roles were recently deleted.

Questions

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

Credits

Thanks to AyushParkara for reporting this vulnerability.

Affected versions

Go

Package	Vulnerable	Fixed in
github.com/zitadel/zitadel	`< 4.16.0`	`4.16.0`
github.com/zitadel/zitadel	`all versions`	No fix yet

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 → `4.16.0`

go

go get github.com/zitadel/zitadel@v4.16.0 && go mod tidy

Severity breakdown

CVSS 3.1 5.5

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

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

Weakness

CWE-193: Off-by-one Error

A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value.

How to prevent it

Implementation: When copying character arrays or using character manipulation methods, the correct size parameter must be used to account for the null terminator that needs to be added at the end of the array. Some examples of functions susceptible to this weakness in C include strcpy(), strncpy(), strcat(), strncat(), printf(), sprintf(), scanf() and sscanf().

References

Packages

github.com/zitadel/zitadel

Timeline

Sep 14, 2026 Published
Sep 17, 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-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
GHSA-wxg7-w2v3-w38g ZITADEL: Missing Token Lifecyle Validation (`exp` and `iat`) in JWT IdP Provider	Medium	Also affects github.com/zitadel/zitadel

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