ZITADEL: Authentication bypass for users of deactivated organizations
Summary
ZITADEL 4.x before 4.17.1 checks only the individual user's status during Login V2 authentication and ignores whether the user's organization has been deactivated. Users of a deactivated organization who still hold valid credentials, an existing session or a refresh token can sign in, create sessions and obtain or refresh tokens. Login V1 is not affected, and sessions and tokens issued before deactivation may remain usable until they expire.
Affected
- ZITADEL 4.x before 4.17.1 (vendor: 4.0.0 through 4.17.0, including RC versions)
- Treat all versions below 4.17.1 as affected. The OSV entry lists a broader range that could not be verified against the vendor advisory.
Fixed in
- Upgrade to ZITADEL 4.17.1 or later. The most recent stable 4.x release is recommended.
Workaround
- Vendor recommendation: upgrade to a patched version.
- If an immediate upgrade is not possible, deactivate affected users individually. User deactivation is enforced and prevents login.
- Review active sessions of users in deactivated organizations and revoke outstanding refresh tokens.
Exploitation
- No public exploitation known.
- CISA SSVC assessment: exploitation none, automatable yes, technical impact partial.
- No public proof of concept found.
Our recommendation
- Inventory all ZITADEL instances and their exact versions.
- Upgrade internet-facing or otherwise exposed instances below 4.17.1 to the latest stable 4.x release, with priority for instances that have deactivated organizations or offboarded users.
- Revoke sessions and refresh tokens of deactivated organizations and review logs for logins or token refreshes since deactivation.
- Subscribe to the GitHub security advisory GHSA-558c-v5wc-9w4q for updates.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- GitHub Security Advisory GHSA-558c-v5wc-9w4q github.com
- VulnCheck advisory www.vulncheck.com
- ZITADEL release v4.17.1 github.com
- OSV entry CVE-2026-105213 osv.dev
- VulDB CVE-2026-105213 vuldb.com
- ZITADEL API documentation: DeactivateOrganization zitadel.com
- Red Packet Security CVE alert CVE-2026-105213 www.redpacketsecurity.com
- threatint CVE record CVE-2026-105213 cve.threatint.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 31 Oct 2026, 22:36.
Original description (NVD)
ZITADEL 4.x before 4.17.1 does not check an organization's inactive state during Login V2 authentication, verifying only the individual user's status. Users of a deactivated organization who hold valid credentials, an existing session, or a refresh token can still sign in, create sessions, and obtain or refresh tokens.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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