CVE-2026-16504
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 · uneditedDeployment of the VPS.org one-click Zulip template deploys a hardcoded application signing key, a default database password ("zulip"), and DISABLE_HTTPS=True.
In the news
Third-party coverageSurfaced from public web coverage — external links open in a new tab.
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 confidenceThe VPS.org one-click Zulip template deploys with a hardcoded application signing key, a default database password ('zulip'), and HTTPS disabled (DISABLE_HTTPS=True), allowing remote attackers to intercept communications, authenticate to the database with default credentials, and potentially forge signed application data.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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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Identify VPS.org one-click Zulip deploymentConfirm whether the Zulip instance was deployed using the VPS.org one-click template by reviewing deployment documentation, cloud-init scripts, or server provisioning recordsAffected if Deployment was performed using the VPS.org one-click Zulip template
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Inspect for hardcoded signing keyExamine Zulip configuration files (typically in /etc/zulip or environment configuration files) for an application signing key that has not been rotated since initial deploymentAffected if A hardcoded application signing key is present and has not been rotated from template defaults
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Check database password configurationReview Zulip configuration files or database connection settings to determine the configured database passwordAffected if The database password is set to the default value 'zulip'
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Verify HTTPS transport settingInspect Zulip environment variables or configuration files for the DISABLE_HTTPS settingAffected if DISABLE_HTTPS is set to True, disabling transport layer encryption
The environment is affected if deployed using the VPS.org one-click Zulip template with any default insecure settings (hardcoded signing key, default 'zulip' password, or DISABLE_HTTPS=True) still in place.
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.
From vendor dataImmediately rotate all hardcoded credentials including the application signing key and database password, and enable HTTPS by setting DISABLE_HTTPS=False in the Zulip configuration.
- Consultation3.0 h
- Implementation5.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,696.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-16504 — 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-2026-16504 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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