OpenBullet2 0.3.2 NTLMv2 Hash Disclosure via UNC Path Proxy Source
CVE-2026-39908

7.1HIGH

Key Information:

Vendor

Openbullet

Status
Openbullet2
Vendor
CVE Published:
8 June 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-39908?

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.

Affected Version(s)

openbullet2 0 <= 0.3.2

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-39908 - Proof of Concept

References

https://hackernoon.com/one-empty-header-to-admin-how-an-a...
technical-descriptionexploit
https://www.vulncheck.com/advisories/openbullet2-ntlmv2-h...
third-party-advisory

CVSS V4

Score:
7.1
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Maksim Rogov
VulnCheck
.