CVE-2026-39908
MediumCVSS 6.5Exploitation Probability (EPSS)
Low risk24th percentile - higher than 24% of all known CVEs
Summary
OpenBullet2 up to version 0.3.2 on Windows has a credential disclosure vulnerability. A remote attacker can configure a proxy source with a UNC path pointing to an attacker-controlled server, causing the application to attempt SMB authentication and leak the NTLMv2 hash of the process user.
Risk Assessment
The leaked NTLMv2 hash can be used for pass-the-hash attacks or offline password cracking, compromising user accounts in a Windows domain.
Recommendation
Upgrade OpenBullet2 to a version later than 0.3.2, or block outbound SMB connections to untrusted servers as a workaround.
Other vulnerabilities in OpenBullet2
See all- CVE-2026-25555Critical
OpenBullet2 through version 0.3.2 has an authentication bypass vulnerability in the API key authentication middleware. Unauthenticated attackers can gain admin access by supplying an empty X-Api-Key header value, as it is compared against a default empty AdminApiKey string.
- CVE-2026-25856High
Vulnerability in OpenBullet2 up to version 0.3.2: authenticated remote code execution via creating or modifying job configurations. The plain C# execution mode lacks reference filtering, allowing access to the file system, process spawning, and arbitrary .NET API calls.
- CVE-2026-25855High
A vulnerability in OpenBullet2 through version 0.3.2 allows authenticated users to execute arbitrary commands by uploading script files (.bat, .ps1, .sh) through the FileProxySource proxy loading feature. Attackers can upload malicious script files as proxy sources, causing the server to execute the scripts and return output as proxy lines, resulting in arbitrary command execution on the host as the process user.
- CVE-2026-25559High
OpenBullet2 through version 0.3.2 contains a path traversal vulnerability in the wordlist endpoint, allowing authenticated attackers to read, write, and delete arbitrary files by supplying unsanitized absolute paths. Attackers can chain these operations to achieve remote code execution by manipulating critical system files such as /etc/passwd, as the application runs as root by default.
Original NVD description (English source)
OpenBullet2 through version 0.3.2 on Windows contains a credential disclosure vulnerability that allows remote attackers to capture the NTLMv2 hash of the process user by configuring a job proxy source with a UNC path pointing to an attacker-controlled server. When the job starts, the application attempts to load proxies from the UNC path, triggering an SMB authentication attempt that discloses the NTLMv2 hash, which can then be relayed or cracked offline.