VULNpocalypse

CVE-2026-111058: Mercury: Unauthenticated Remote Code Execution via /api/kernels

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.

Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.

What it is

Mercury is a Python framework for sharing Jupyter notebooks as web applications and dashboards. Prior to 3.2.6, default tokenless deployments allow anonymous clients to create Jupyter kernels and send execute_request messages containing arbitrary Python. The endpoint blocklist does not cover /api/kernels, and the websocket wrapper previously tracked idle activity without authorizing executable messages. This issue is fixed in version 3.2.6.

Description quoted from the CVE record (assigned by GitHub_M, published 2026-10-19).

Weakness: CWE-862: Missing Authorization

How it can be exploited

Exploitable over the network with low attack complexity needing no privileges and no user interaction. Impact: 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

CISA assessment (SSVC): CISA has no evidence of exploitation. Automatable: yes. Technical impact: total.

Public exploit evidence (Exploit Observer)

Also known as: BDU:2026-17113, EUVD-2026-104420, GHSA-rv4m-xm3f-3ccq

VEDAS cluster: VEDAS:DIVINEDURIAN

Exploit Observer links 6 pieces of public exploit code or detection modules that name this CVE or one of its aliases.

Exploit code and modules (6)

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.

3 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
0.005
low predicted chance of attack
VEDAS
0.990
strong exploit evidence
On CISA KEV
Not listed
Detection rule
Nuclei · Suricata

Who is affected

ProductAffectedNot affected
mljar mercuryversion < 3.2.6Not stated

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

Exploit Observer also maps it to: pypi mercury, сообщество_свободного_программного_обеспечения mercury.

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)

Mercury - Missing Authorization

In mljar Mercury prior to 3.2.6, default tokenless deployments allow anonymous clients to create Jupyter kernels and send execute_request messages containing arbitrary Python. The anonymous endpoint blocklist does not cover `/api/kernels`, so an unauthenticated attacker can POST to that endpoint to spin up a kernel and subsequently execute code as the Mercury process.

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

The template sends 1 request (POST /api/kernels); it decides using dsl matchers. Severity in the template: critical. 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-2026-111058.yaml
Show the template (39 lines)
yaml
id: CVE-2026-111058

info:
  name: "Mercury - Missing Authorization"
  author: vedas-arpsyndicate
  severity: critical
  description: |
    In mljar Mercury prior to 3.2.6, default tokenless deployments allow anonymous clients to
    create Jupyter kernels and send execute_request messages containing arbitrary Python. The
    anonymous endpoint blocklist does not cover `/api/kernels`, so an unauthenticated attacker
    can POST to that endpoint to spin up a kernel and subsequently execute code as the Mercury
    process.
  reference:
    - https://www.exploit.observer/?keyword=CVE-2026-111058&match=exact
    - https://subdomain.center/?engine=ammonites&keyword=mercury&match=exact
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2026-111058
    cwe-id: CWE-862
  metadata:
    verified: false
  tags: cve,cve2026,mercury,auth-bypass
http:
  - raw:
      - |
        POST /api/kernels HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/json

        {"name":"python3"}

    matchers:
      - type: dsl
        dsl:
          - 'contains_all(body, "\"id\"", "\"execution_state\"")'
          - 'contains(content_type, "application/json")'
          - 'status_code == 200 || status_code == 201'
        condition: and

CVE-2026-111058.yaml on GitHub

Suricata rules (network detection)

1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-111058 Mercury - Missing Authorization. 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-2026-111058 Mercury - Missing Authorization"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/api/kernels"; nocase; fast_pattern; classtype:web-application-attack; reference:cve,CVE-2026-111058; reference:url,https://www.exploit.observer/?keyword=CVE-2026-111058&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=mercury&match=exact; sid:1080401; rev:1;)

CVE-2026-111058.rules on GitHub

References

Other references

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.