CVE-2026-39908
OpenBullet2 0.3.2 NTLMv2 Hash Disclosure via UNC Path Proxy Source
Description
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.
INFO
Published Date :
June 8, 2026, 5:16 p.m.
Last Modified :
June 8, 2026, 5:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-39908
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update OpenBullet2 to version 0.3.3 or later.
- Configure job proxy sources carefully.
- Avoid using UNC paths for proxy sources.
- Monitor network traffic for suspicious SMB connections.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-39908.
| URL | Resource |
|---|---|
| https://hackernoon.com/one-empty-header-to-admin-how-an-auth-bypass-breaks-openbullet2 | |
| https://www.vulncheck.com/advisories/openbullet2-ntlmv2-hash-disclosure-via-unc-path-proxy-source |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-39908 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-39908
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-39908 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-39908 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Jun. 08, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/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 Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-522 Added Reference https://hackernoon.com/one-empty-header-to-admin-how-an-auth-bypass-breaks-openbullet2 Added Reference https://www.vulncheck.com/advisories/openbullet2-ntlmv2-hash-disclosure-via-unc-path-proxy-source