CVE-2026-27945
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedZITADEL is an open source identity management platform. Zitadel Action V2 (introduced as early preview in 2.59.0, beta in 3.0.0 and GA in 4.0.0) is a webhook based approach to allow developers act on API request to Zitadel and customize flows such the issue of a token. Zitadel's Action target URLs can point to local hosts, potentially allowing adversaries to gather internal network information and connect to internal services. When the URL points to a local host / IP address, an adversary might gather information about the internal network structure, the services exposed on internal hosts etc. This is sometimes called a Server-Side Request Forgery (SSRF). Zitadel Actions expect responses according to specific schemas, which reduces the threat vector. The patch in version 4.11.1 resolves the issue by checking the target URL against a denylist. By default localhost, resp. loopback IPs are denied. Note that this fix was only released on v4.x. Due to the stage (preview / beta) in which the functionality was in v2.x and v3.x, the changes that have been applied to it since then and the severity, respectively the actual thread vector, a backport to the corresponding versions was not feasible. Please check the workaround section for alternative solutions if an upgrade to v4.x is not possible. If an upgrade is not possible, prevent actions from using unintended endpoints by setting network policies or firewall rules in one's own infrastructure. Note that this is outside of the functionality provided by Zitadel.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceZITADEL Action V2 contains an SSRF vulnerability where webhook target URLs can point to localhost or loopback IP addresses, allowing adversaries to probe internal network services and gather network topology information. The patch in v4.11.1 adds a denylist check to block localhost and loopback addresses.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 2.59.0, <= 3.4.6>= 4.0.0, < 4.11.1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check ZITADEL versionLocate your installed ZITADEL version via the admin console, helm chart values, or the binary/container image tag. Compare it against the affected ranges: v2.59.0 through v3.4.6, or v4.0.0 through v4.11.0.Affected if The installed version falls within any of the affected ranges.
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Identify Actions using HTTP requestsIn the ZITADEL console, navigate to the Actions/Workflows section and review all defined actions. Identify any actions configured to make HTTP outgoing requests, particularly those with webhook or callback configurations.Affected if You have Actions configured that make outbound HTTP requests.
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Inspect webhook target URLsFor each action that makes HTTP requests, examine the target URL field. Check if any URL resolves to 127.0.0.1, localhost, or any loopback address range (127.0.0.0/8).Affected if Any webhook or HTTP action target URL points to localhost or a loopback IP address.
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Review internal network targetsExamine all HTTP action URLs for targets that could access internal services, including private IP ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) or internal hostnames that could resolve to infrastructure services.Affected if HTTP action URLs target internal network addresses or services.
You are affected if your ZITADEL version is between v2.59.0 and v3.4.6, or between v4.0.0 and v4.11.0, AND you have Actions configured with webhook URLs that point to localhost, loopback, or internal network addresses.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped4.11.1
Upgrade to ZITADEL v4.11.1 or later which implements a denylist blocking localhost/loopback URLs; alternatively, enforce network policies or firewall rules to block unintended internal connections.
4.11.1
- Upgrade Zitadel to version 4.11.1 or later to receive the SSRF protection fix
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-27945 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-27945 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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