CVE-2026-55671 ZITADEL: Server-Side Request Forgery (SSRF) and Denylist Bypass in Outgoing HTTP Components
Attackers can bypass URL denylists to force the server to make requests to internal or protected endpoints via DNS rebinding or redirects.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-55671?
CVE-2026-55671 is a low-severity server-side request forgery vulnerability in zitadel, published on 10 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
ZITADEL is an open source identity management platform. From 4.0.0-rc.1 through 4.15.1, ZITADEL's HTTP notification channels, OIDC BackChannel Logout, and SAML metadata URL fetches do not consistently validate user-defined URLs against protected denylist handling, allowing server-side requests to loopback, internal IP, link-local, or redirected endpoints through DNS rebinding, redirects, or protocol downgrades. This issue is fixed in version 4.15.2.
Weakness: CWE-918
Which versions are affected by CVE-2026-55671?
3 open source packages ship an affected version, including github.com/zitadel/zitadel.
| Package | Affected | Fixed in |
|---|---|---|
github.com/zitadel/zitadel Go | All versions | 1.80.0-v2.20.0.20260615133614-8e82ec1cb9a2 |
github.com/zitadel/zitadel Go | All versions | 1.80.0-v2.20.0.20260615133614-8e82ec1cb9a2 |
github.com/zitadel/zitadel Go | All versions | 1.80.0-v2.20.0.20260615133614-8e82ec1cb9a2 |
How do I fix CVE-2026-55671?
Upgrade github.com/zitadel/zitadel to 1.80.0-v2.20.0.20260615133614-8e82ec1cb9a2 or later.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-55671 being exploited?
There is no known exploitation of CVE-2026-55671 in the wild and no public exploit code.
Sources
Also known as GHSA-29jh-8cfq-rr8x, GO-2026-5059.