Description
OpenBullet2 through version 0.3.2 contains an authentication bypass vulnerability in the API key authentication middleware that allows unauthenticated attackers to gain admin access by supplying an empty X-Api-Key header value. Attackers can exploit the middleware's comparison of the supplied header against an empty AdminApiKey default string to access the admin console and all API endpoints without valid credentials.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| openbullet | openbullet2 | ≤ 0.3.2 | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Metasploit 2 modules
-
OpenBullet2 Unauthenticated RCE via Config Configuration Interface
exploit/multi/http/openbullet2_unauth_rce_cve_2026_25856
-
OpenBullet2 NTLMv2 Hash Disclosure via UNC Path Proxy Source
auxiliary/scanner/http/openbullet2_unauth_hash_disclosure_cve_2026_39908
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Automated scanner template
A ready-made Nuclei template detects this vulnerability automatically. Vulnerabilities with public scanner templates are typically probed across the internet soon after the template appears — exposed systems should be patched first.
- OpenBullet2 <= 0.3.2 - Authentication Bypass http/cves/2026/CVE-2026-25555.yaml
Source: projectdiscovery/nuclei-templates (MIT) — updated daily. Only links are listed.
References
- https://hackernoon.com/one-empty-header-to-admin-how-an-auth-bypass-breaks-openbullet2 technical-description exploit
- https://www.vulncheck.com/advisories/openbullet2-authentication-bypass-via-x-api-key-header third-party-advisory