CVE-2026-40139
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 · uneditedA critical pre-authentication vulnerability exists in the authentication subsystem of BeyondTrust Remote Support. Improper processing of authentication requests may allow an unauthenticated remote attacker to bypass access controls and gain unauthorized access to the appliance, including accounts with elevated privileges. Exploitation requires a specific authentication configuration to be enabled.
In the news
Third-party coverage- BeyondTrust Patches Critical Auth Bypass Flaws in Remote Support ...
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Surfaced from public web coverage — external links open in a new tab.
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 · moderate confidenceA pre-authentication bypass vulnerability in BeyondTrust Remote Support's authentication subsystem allows unauthenticated remote attackers to bypass access controls and gain unauthorized access to the appliance, including accounts with elevated privileges. Exploitation is conditional on a specific authentication configuration being enabled.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 25.3.3< 25.3.3CVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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 the installed BeyondTrust product and versionLocate the BeyondTrust application on the appliance and determine its version number. This is typically visible in the product's web interface, about page, or system information panel. For command-line environments, check the product's service information or installed packages.Affected if The installed version is below 25.3.3 for either Beyondtrust Privileged Remote Access or Beyondtrust Remote Support.
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Compare your version to the affected rangeVerify the exact version number found against the vulnerable range: versions prior to 25.3.3 are affected. Note that only versions before the 25.3.3 patch are vulnerable.Affected if Your installed version is less than 25.3.3.
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Locate the specific authentication configurationAccess the BeyondTrust administrative interface and navigate to the authentication settings section. Identify the authentication configuration referenced in the BeyondTrust security advisory for this CVE - this is the particular setting that must be present for exploitation to succeed.Affected if The specific authentication configuration mentioned in the CVE advisory is present and enabled on your appliance.
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Verify the configuration stateConfirm whether the vulnerable authentication configuration is currently active. Check both the primary authentication settings and any secondary or fallback authentication methods configured.Affected if The vulnerable authentication configuration is enabled.
You are affected only if your installed version is below 25.3.3 AND the specific authentication configuration referenced in the BeyondTrust advisory is enabled on your appliance.
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.
dbcve · scoped25.3.3
Identify and remediate the specific authentication configuration that enables exploitation; apply vendor-supplied patches immediately; review all account access and audit for unauthorized activity.
Upgrade to version 25.3.3 or later for both Privileged Remote Access and Remote Support
- Identify which BeyondTrust product is deployed: Privileged Remote Access or Remote Support
- Check the current version of the appliance to confirm it is below version 25.3.3
- Download the fixed version 25.3.3 from the BeyondTrust customer portal or official download source
- Apply the upgrade following BeyondTrust standard upgrade procedures for your deployment type
- After upgrade, verify the version has been updated to 25.3.3 or later
- Review authentication configuration settings as noted in the vulnerability description - ensure no insecure authentication configurations are enabled
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation6.0 h
- Implementation8.0 h
- Testing10.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,776.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-40139 — 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-2026-40139 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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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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
- No spam, self-promotion, credentials, or personal data