CVE-2026-55672
HIGHZITADEL: Missing client_id binding in OIDC authorization code exchange and refresh token flows (RFC 6749 Section 4.1.3 violation)
Blast Radius
github.com/zitadel/zitadelReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
ZITADEL is an open source identity management platform. Prior to 3.4.12 and 4.15.2, ZITADEL's OAuth2 and OIDC CodeExchange, RefreshToken, and device token flows fail to verify that the requesting client matches the client that initiated the authorization flow, allowing intercepted grants or refresh tokens to be exchanged under a different client. This issue is fixed in versions 3.4.12 and 4.15.2.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/zitadel/zitadel | all versions | 1.80.0-v2.20.0.20260616131956-0973b074b488 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/zitadel/zitadel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/zitadel/zitadel to 1.80.0-v2.20.0.20260616131956-0973b074b488 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-55672 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-55672 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-55672. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-55672 in your dependencies?
O3 detects CVE-2026-55672 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.