CVE-2026-39908
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedOpenBullet2 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceOpenBullet2 versions up to 0.3.2 on Windows contains an NTLMv2 credential disclosure vulnerability. Attackers configure a job proxy source with a UNC path (\\attacker-server\share) pointing to their controlled SMB server. When the application starts the job and attempts to load proxies from this UNC path, it triggers an SMB authentication handshake that transmits the process user's NTLMv2 hash to the attacker, who can then relay or crack it offline.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify OpenBullet2 installation and versionSearch for OpenBullet2 installation directories (typically under C:\Program Files\, C:\Users\%username%\AppData\, or custom install paths). Look for the executable (OpenBullet2.exe, OpenBullet2.dll, or version.json). Check the version file or file properties for version 0.3.2.Affected if OpenBullet2 version 0.3.2 is installed on a Windows system.
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Locate job configuration files with UNC proxy sourcesSearch the OpenBullet2 data directory (Configs/Jobs or similar) for job configuration files (.json, .ob2, or config files). Inspect each file for a proxy source setting that uses a UNC path format (\\hostname\sharename or \\IP\sharename).Affected if Any job configuration specifies a proxy source using a UNC path (\\server\share format).
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Review job execution historyCheck OpenBullet2 logs (Logs folder), run history, or database for records of job executions. Look for entries indicating jobs with UNC proxy sources were executed, which would trigger the SMB authentication handshake.Affected if A job configured with a UNC proxy source has been executed, causing the application to attempt loading proxies from the UNC path.
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Inspect SMB/network connection logsReview Windows Event Viewer Security logs (Event ID 4624 for successful logons, 4625 for failures), SMB client logs, or any available network monitoring data for outbound SMB connections from the OpenBullet2 process to unexpected or attacker-controlled IP addresses.Affected if Outbound SMB connections (port 445) were made from the OpenBullet2 host to untrusted or external IP addresses.
You are affected if OpenBullet2 version 0.3.2 is installed, contains any job configurations using UNC paths as proxy sources, and those jobs have been executed, resulting in NTLMv2 hash disclosure to an external SMB server.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataDisable NTLM authentication and enforce Kerberos authentication where possible, or block outbound SMB connections (ports 445/139) at the network perimeter to prevent the application from reaching attacker-controlled servers.
- Consultation3.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-39908 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-39908 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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