Description
Frappe Builder versions 1.33.0 before1.36.0 contain a missing authorization vulnerability in the improve_prompt endpoint that allows any authenticated non-Guest session to invoke LLM completions without proper permission checks. Attackers can call the improve_prompt API to leverage the site owner's stored OpenRouter API key via resolve_api_key, consuming paid LLM credits and effectively turning the site into a free LLM proxy.
Published: 2026-10-26
Score: 5.3 Medium
EPSS: n/a
KEV: No
Impact: Unauthorized Use of Stored LLM API Key
Action: Immediate Patch
AI Analysis

Impact

Frappe Builder’s improve_prompt endpoint has a missing authorization flaw (CWE‑862). An authenticated non‑guest user can call the API, triggering LLM completions that use the site owner's stored OpenRouter API key and consume paid credits, effectively turning the site into a free LLM proxy and potentially causing financial loss.

Affected Systems

All Frappe Builder releases from version 1.33.0 up to, but not including, 1.36.0 are affected. The issue is fixed in the 1.36.0 release as documented in the advisory.

Risk and Exploitability

The CVSS score of 5.3 indicates medium risk, EPSS data is missing, and the vulnerability is not listed in CISA’s KEV catalog. Exploitation requires an authenticated, non‑guest session, so the threat primarily presents an economic risk from unauthorized credit usage.

Generated by OpenCVE AI on October 26, 2026 at 13:23 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade Frappe Builder to version 1.36.0 or later, which removes the missing authorization check in improve_prompt.
  • Rotate or revoke the OpenRouter API key stored in your Frappe site to limit the potential damage if the vulnerability is still present or the upgrade is pending.
  • Review and tighten permission settings for authenticated users, ensuring that only authorized roles can access LLM completion endpoints.
  • Monitor LLM usage logs for unexpected traffic and set alerts for large out‑of‑band requests to detect potential abuse.

Generated by OpenCVE AI on October 26, 2026 at 13:23 UTC.

Tracking

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Advisories

No advisories yet.

History

Mon, 26 Oct 2026 12:15:00 +0000

Type Values Removed Values Added
Description Frappe Builder versions 1.33.0 before1.36.0 contain a missing authorization vulnerability in the improve_prompt endpoint that allows any authenticated non-Guest session to invoke LLM completions without proper permission checks. Attackers can call the improve_prompt API to leverage the site owner's stored OpenRouter API key via resolve_api_key, consuming paid LLM credits and effectively turning the site into a free LLM proxy.
Title Frappe Builder 1.33.0 before 1.36.0 Missing Authorization via improve_prompt
First Time appeared Frappe
Frappe builder
Weaknesses CWE-862
CPEs cpe:2.3:a:frappe:builder:*:*:*:*:*:*:*:*
Vendors & Products Frappe
Frappe builder
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L'}

cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}

Subscriptions

Frappe Builder
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-26T16:17:17.612Z

Reserved: 2026-10-23T11:13:54.116Z

Link: CVE-2026-115718

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-10-26T12:17:05.387

Modified: 2026-10-26T17:17:17.487

Link: CVE-2026-115718

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-26T18:50:59Z

Weaknesses