CVE-2026-25555OpenBullet2 0.3.2 Authentication Bypass via X-Api-Key Header
- 9.3CriticalCVSS base score
- 2.3%Exploitation in 30 daysEPSS · top 17% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- 3Public exploitsMetasploit, Nuclei and Exploit-DB
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. The public collections list 2 Metasploit modules and a Nuclei template for it. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits4
Metasploit modules2 modules
- OpenBullet2 NTLMv2 Hash Disclosure via UNC Path Proxy Source (Metasploit module) (opens in a new tab)
auxiliary/scanner/http/openbullet2_unauth_hash_disclosure_cve_2026_39908Rank normaldisclosed 8 Jun 2026
- OpenBullet2 Unauthenticated RCE via Config Configuration Interface (Metasploit module) (opens in a new tab)
exploit/multi/http/openbullet2_unauth_rce_cve_2026_25856Rank excellentdisclosed 8 Jun 2026
Nuclei templates1 template
- OpenBullet2 <= 0.3.2 - Authentication Bypass (Nuclei template) (opens in a new tab)
http/cves/2026/CVE-2026-25555.yamlSeverity critical
References tagged exploit1 reference
- https://hackernoon.com/one-empty-header-to-admin-how-an-auth-bypass-breaks-openbullet2 (opens in a new tab)technical-descriptionexploit
Modules, templates and exploits as listed by the Metasploit Framework (BSD-3-Clause), ProjectDiscovery's Nuclei templates (MIT) and the Exploit Database (GPLv2), read once a day. Where the data comes from
Timeline
ID reserved
By VulnCheck
- 4 months later
· 4 months later
Published
- 36 days later
· 36 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulnCheckCNA (assigner) | 4.0 | Critical9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| VulnCheckCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Deferred | 4.0 | Critical9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 2.3% · top 17% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.3.
Affected products
- affected ≤ 0.3.2
References
References2
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-35138 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-25555)Record last updated .