CVE-2026-11746: Central Dogma: Hard-coded ZooKeeper replication secret 'ch4n63m3' with silent fallback enables cluster takeover

Should you act?

Critical, preconditions apply

Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
• EPSS 0.2%, percentile 13: FIRST’s model estimates a 0.2% chance of exploitation activity in the next 30 days, higher than 13% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Only applies if your dependency tree includes com.linecorp.centraldogma:centraldogma-server (Maven) < 0.84.0, fixed in 0.84.0. Check your lockfile, including transitive dependencies.

What it is

A vulnerability has been identified in centraldogma-server versions prior to 0.84.0, where enabling ZooKeeper replication without setting replication.secret causes the server to silently fall back to a hard-coded, publicly known secret. This default credential authenticates the embedded ZooKeeper ensemble, allowing an attacker with network access to read the full replication log or join the quorum and execute arbitrary replicated commands across the cluster.

From the GitHub advisory

Vulnerability

ZooKeeperReplicationConfig.secret() silently substitutes the hard-coded constant "ch4n63m3" (leetspeak for "change me") whenever the operator omits replication.secret. The same secret is wired into both the client-facing SASL context and the quorum/learner SASL contexts of the embedded ZooKeeper. The constant is in OSS source on GitHub and is discoverable via code search in seconds.

Three Reinforcing Defects

1. OSS-public credential — DEFAULTSECRET is in line/centraldogma source. 2. Silent fallback — firstNonNull(convertValue(...), DEFAULTSECRET) substitutes the default with no log, no warning, no startup banner. The only sanity check checkArgument(!secret().isEmpty(), ...) passes because the getter substitutes the literal before the emptiness check runs. 3. Dual-purpose secret — used for both ZK client-port super auth and inter-peer quorum SASL. A single leaked password authenticates against both surfaces.

Architecture Context (Important)

Weakness type: CWE-798.

Product: com.linecorp.centraldogma:centraldogma-server (Maven) · Assigned by: LY-Corporation · Published: 2026-06-22

Affected and fixed versions

Severity scores

• Attack vector: adjacent network only
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation poc, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.23% probability of exploitation activity in the next 30 days; percentile 13.

Timeline

• 2026-06-22 — CVE record last updated
• 2026-06-22 — CVE record published by LY-Corporation
• 2026-09-11 — GitHub-reviewed advisory GHSA-2j95-gqxf-v3vg published (critical)

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-2j95-gqxf-v3vg github.com
2. CVE.org record CVE-2026-11746 cve.org
3. NVD entry CVE-2026-11746 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com

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