SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-25555

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.

CRITICAL 9.3EPSS 1.82%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.82%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0
9.3 CRITICALCVSS: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/M
EPSS
1.82% probability · 79th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-305
Source
disclosure@vulncheck.com
EPSS trend
0%3%5%26 October 2026: 1.82%26 October 202626 October 2026

EPSS 1.8% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.