CVE-2026-39908 json
OpenBullet2 0.3.2 NTLMv2 Hash Disclosure via UNC Path Proxy Source
published 2026-06-08 5 mo ago modified 2026-07-23 3 mo ago also EUVD-2026-35133
- cvss
- 6.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.8%
- EPSS 0.8% chance of exploitation in 30 days, percentile 57%
- public exploits
- 1
- Metasploit
Summary
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.
Timeline
- First public exploit (Metasploit auxiliary/scanner/http/openbullet2_unauth_hash_disclosure_cve_2026_39908)
- Published
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 5 mo ago
Exploit prediction
0.82% chance of exploitation in the next 30 days, higher than 57% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- Metasploit auxiliary/scanner/http/openbullet2_unauth_hash_disclosure_cve_2026_39908 OpenBullet2 NTLMv2 Hash Disclosure via UNC Path Proxy Source metasploit auxiliary, normal rank, 2026-06-08
- hackernoon.com https://hackernoon.com/one-empty-header-to-admin-how-an-auth-bypass-breaks-openbullet2 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 7.1 | 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 |
| CNA | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
| CNA | 4.0 | 7.1 | 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:X/V:X/RE:X/U:X |
Affected products
- openbullet openbullet2
Classification
- Weakness
-
- CWE-522 Insufficiently Protected Credentials
References
-
hackernoon.com
/one-empty-header-to-admin-how-an-auth-bypass-breaks-openbullet2
technical-description, exploit
-
vulncheck.com
/advisories/openbullet2-ntlmv2-hash-disclosure-via-unc-path-proxy-source
third-party-advisory
Sources
- CVE List CVE-2026-39908
- NVD CVE-2026-39908
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