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Vulnerability record · CVE-2026-39908 · published 8 June 2026

CVE-2026-39908: Insufficiently protected credentials vulnerability

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.

7.1 CVSS 4.0 High EPSS 0.54% · top 56.9% CWE-522 · Insufficiently protected credentials Deferred
7.1CVSS 4.0 base score
0.54%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
2References
23 Jul 2026Last modified by NVD

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.

CVSS:4.0/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:

References

LinkTags
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

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Source: NIST National Vulnerability Database (record CVE-2026-39908), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.