CVE-2026-59148: mockoon mockoon advisory

Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.

What it is

Mockoon provides way to design and run mock APIs. Prior to 9.7.0, Mockoon’s admin API in commons-server/src/libs/server/admin-api.ts is mounted on the same Express listener as user-defined mock routes, enabled by default in shipped runtimes, serves Access-Control-Allow-Origin: * with write methods allowed, and has no authentication. Any unauthenticated caller who can reach the mock server port can read MOCKOON_* environment variables, write arbitrary process environment variables through /mockoon-admin/env-vars, rewrite mock route bodies, statuses, and headers through PUT /mockoon-admin/environment, read transaction logs and SSE streams, and purge state. This issue is fixed in version 9.7.0.

Description quoted from the CVE record (assigned by GitHub_M, published 2026-07-09).

Weakness: CWE-306: Missing Authentication for Critical Function; CWE-352: Cross-Site Request Forgery (CSRF); CWE-732: Incorrect Permission Assignment for Critical Resource; CWE-942: Permissive Cross-domain Policy with Untrusted Domains

How it can be exploited

Exploitable over the network with low attack complexity needing no privileges and a user must take an action. Impact: confidentiality high, integrity high, availability high. CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CISA assessment (SSVC): CISA assesses that a public proof of concept exists. Automatable: no. Technical impact: total.

Public exploit evidence (Exploit Observer)

Also known as: EUVD-2026-42683, GHSA-rqx4-3f6q-3x2v

VEDAS cluster: VEDAS:CYCLONEGLOW

Exploit Observer links 5 pieces of public exploit code or detection modules that name this CVE or one of its aliases.

Exploit code and modules (5)

Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.

Vulnerability databases and vendor advisories (5)

Catalogue entries, not exploit evidence.

Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2026-42683
Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-rqx4-3f6q-3x2v
Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-59148
Vulnerability database or vendor advisory: https://osv.dev/vulnerability/CVE-2026-59148
Vulnerability database or vendor advisory: https://osv.dev/vulnerability/GHSA-rqx4-3f6q-3x2v

2 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.

VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.

Live scores

EPSS: 0.003
low predicted chance of attack
VEDAS: 0.987
strong exploit evidence
On CISA KEV: Not listed
Detection rule: Nuclei · Suricata

Who is affected

Product	Affected	Not affected
mockoon mockoon	version < 9.7.0	Not stated

Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.

How to fix it

No fixed version or vendor advisory is listed in the CVE record yet. Watch the vendor’s security page.

How to detect it

Nuclei template (active check)

Mockoon - Unauthenticated Admin API Exposure
Mockoon prior to 9.7.0 mounts its admin API on the same Express listener as the user-defined mock routes, enabled by default in shipped runtimes, and enforces no authentication. Any unauthenticated caller that can reach the mock server port can access the /mockoon-admin endpoints to read and write MOCKOON_* process environment variables (/mockoon-admin/env-vars), rewrite mock route bodies, statuses and headers (PUT /mockoon-admin/environment), read transaction logs and SSE streams, and purge state. The admin API root (GET /mockoon-admin) returns a distinctive welcome banner without credentials, which confirms the admin API is reachable unauthenticated. Fixed in 9.7.0, which adds a bearer-token guard.

Name and description quoted from the template, written by VEDAS.

The template sends 1 request (GET /mockoon-admin); it decides using status, word matchers. Severity in the template: high. Marked as not yet verified against a live vulnerable target.

Run it against a host you own or are authorised to test:

bash

nuclei -u https://your-host -t CVE-2026-59148.yaml

Show the template (40 lines)

yaml

id: CVE-2026-59148

info:
  name: "Mockoon - Unauthenticated Admin API Exposure"
  author: vedas-arpsyndicate
  severity: high
  description: |
    Mockoon prior to 9.7.0 mounts its admin API on the same Express listener as the user-defined mock
    routes, enabled by default in shipped runtimes, and enforces no authentication. Any unauthenticated
    caller that can reach the mock server port can access the /mockoon-admin endpoints to read and write
    MOCKOON_* process environment variables (/mockoon-admin/env-vars), rewrite mock route bodies, statuses
    and headers (PUT /mockoon-admin/environment), read transaction logs and SSE streams, and purge state.
    The admin API root (GET /mockoon-admin) returns a distinctive welcome banner without credentials, which
    confirms the admin API is reachable unauthenticated. Fixed in 9.7.0, which adds a bearer-token guard.
  reference:
    - https://www.exploit.observer/?keyword=CVE-2026-59148&match=exact
    - https://subdomain.center/?engine=ammonites&keyword=mockoon&match=exact
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
    cvss-score: 8.8
    cve-id: CVE-2026-59148
    cwe-id: CWE-306
  metadata:
    verified: false
    max-request: 1
  tags: cve,cve2026,mockoon,exposure,auth-bypass,unauth

http:
  - method: GET
    path:
      - "{{BaseURL}}/mockoon-admin"
    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - "Welcome to Mockoon's admin API"
      - type: status
        status:
          - 200

CVE-2026-59148.yaml on GitHub

Suricata rules (network detection)

1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-59148 Mockoon - Unauthenticated Admin API Access Attempt. Add them to your Suricata rule set and reload.

Show the rules

suricata

alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-59148 Mockoon - Unauthenticated Admin API Access Attempt"; flow:established,to_server; http.uri; content:"/mockoon-admin"; nocase; fast_pattern; classtype:web-application-attack; reference:cve,CVE-2026-59148; reference:url,https://www.exploit.observer/?keyword=CVE-2026-59148&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=mockoon&match=exact; sid:1097600; rev:1;)

CVE-2026-59148.rules on GitHub

References

Other references

https://github.com/mockoon/mockoon/security/advisories/GHSA-rqx4-3f6q-3x2v (x_refsource_CONFIRM)
https://github.com/mockoon/mockoon/pull/2254 (x_refsource_MISC)
https://github.com/mockoon/mockoon/commit/c420b5a56918475b8663977b51e5f986e45b3299 (x_refsource_MISC)
https://github.com/mockoon/mockoon/releases/tag/v9.7.0 (x_refsource_MISC)
https://mockoon.com/releases/9.7.0 (x_refsource_MISC)

Other databases

Where this comes from

This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.