Skip to main content
VulnerabilityPublished

CVE-2026-120338: PrefectHQ prefab-ui · Protection Mechanism Failure

Affects PrefectHQ prefab-uiSource CVE Database V5

0
Compare

Not known to be exploited · CVSS 10.0 Critical : upgrade to 0.21.0 as a priority.

Data as of 1 Nov 2026, 15:45 UTC

CVSS 3.1 base score
10.0Critical
How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none
CVSS scores by source
CNA (JFROG)CVSS 3.110.0
CNA (JFROG)CVSS 3.19.9
Patch
Available – fixed in 0.21.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 1 Nov 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 1 Nov 2026.

What to do

Upgrade PrefectHQ prefab-ui to 0.21.0.

Affected software

ProductAffectedFixed in
PrefectHQprefab-uiAffected
  • >=0.14.0 <0.21.0
Fixed in
  • 0.21.0
PyPIprefab-uipkg:pypi/prefab-uiOther threatsAffected
  • >=0.14.0 <0.21.0
Fixed in
  • 0.21.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade prefab-ui to version 0.21.0 or later, where the vulnerability is fixed by revoking Deno read, write, and network permissions before accepting untrusted code and restricting network access to cdn.jsdelivr.net. Ensure that authentication is properly configured to restrict access to the Generative UI tool.

Description

PrefabHQ prefab-ui versions 0.14.0 through 0.20.2 contain a critical protection mechanism failure in their Generative UI sandbox. The sandbox runs caller-supplied Python code inside Pyodide within a Deno subprocess but starts Deno with unrestricted read, write, and network permissions. This allows an attacker supplying code to read and write files as the server OS user and persist code execution by writing files into the server's virtual environment. The vulnerability is fixed in version 0.21.0 by revoking these permissions before accepting code and restricting network access.

References

Community reviews

Loading reviews…