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Server-Side Request Forgery (SSRF)Weakness · CWE-918

CVE-2026-33975

HIGH · 8.3 CVSS v4.0 Published 2026-05-05
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
89/100
Remediation priority · High
Remotely reachable Zero-click

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 · unedited
Twenty is an open source CRM built with NestJS (Node.js). In versions 1.18.0 and earlier, the SSRF protection in twenty-server's SecureHttpClientService can be bypassed using IPv4-mapped IPv6 addresses in URL IP literals. Node.js's URL parser normalizes IPv4-mapped IPv6 addresses to compressed hex form (e.g., ::ffff:169.254.169.254 becomes ::ffff:a9fe:a9fe), but the isPrivateIp utility only recognizes the dotted-decimal notation. As a result, the hex form passes the SSRF check unchecked. Additionally, the socket lookup validation event does not fire for IP literal addresses, bypassing the second validation layer. An authenticated user can reach any internal IP, including cloud metadata endpoints, to exfiltrate credentials such as IAM keys.

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 confidence

The SSRF protection in twenty-server's SecureHttpClientService can be bypassed using IPv4-mapped IPv6 addresses. Node.js normalizes addresses like ::ffff:169.254.169.254 to hex form ::ffff:a9fe:a9fe, but the isPrivateIp utility only checks dotted-decimal notation, allowing authenticated users to bypass the check and reach internal/cloud metadata endpoints to exfiltrate IAM credentials.

MitigationUpgrade to a version after 1.18.0 that properly validates IPv4-mapped IPv6 addresses in hex form and ensures socket lookup validation fires for IP literal addresses.

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
Low
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify Twenty CRM version
    Check the installed package version (e.g., via npm list, package.json, or equivalent dependency file) and compare to known affected versions
    Affected if The installed version falls within the range containing the vulnerable SecureHttpClientService with the isPrivateIp bypass flaw
  2. Locate the SecureHttpClientService module
    Find the SecureHttpClientService file in the Twenty CRM codebase - typically in a services or http directory - and confirm it imports or uses an isPrivateIp validation function
    Affected if The SecureHttpClientService is present and utilizes an isPrivateIp check for outbound HTTP requests
  3. Examine isPrivateIp utility implementation
    Open the isPrivateIp utility source code and verify whether it validates IPv4-mapped IPv6 addresses in compressed hex form (e.g., ::ffff:a9fe:a9fe) in addition to dotted-decimal notation
    Affected if The isPrivateIp function only checks dotted-decimal format (169.254.x.x) and does not validate compressed hex IPv6 representations of private addresses
  4. Verify socket lookup validation for IP literals
    Check the SecureHttpClientService code for DNS/socket resolution validation logic - confirm whether it triggers for IP literal addresses or only for hostname-based URLs
    Affected if Socket lookup validation is skipped for IP literal addresses, allowing direct connections to internal/cloud metadata IPs

A user is affected if they run a Twenty CRM version containing the vulnerable SecureHttpClientService where the isPrivateIp utility fails to block compressed hex IPv4-mapped IPv6 addresses or where socket validation is bypassed for IP literals.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to a version after 1.18.0 that properly validates IPv4-mapped IPv6 addresses in hex form and ensures socket lookup validation fires for IP literal addresses.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-33975 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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