CVE-2026-40139: remote support Auth Bypass — Fix

Description

A 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.

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CVSS v3.1 Score

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0065

Probability of exploitation

0.47%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-287 Improper Authentication

Affected Products

Vendor	Product	Versions
beyondtrust	privileged_remote_access	< 25.3.3
beyondtrust	remote_support	< 25.3.3

References

Advisories & Patches

https://www.beyondtrust.com/trust-center/security-advisories/bt26-03

Frequently Asked Questions

What is CVE-2026-40139? +

A 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. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2026-40139? +

CVE-2026-40139 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0065, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-40139? +

CVE-2026-40139 affects products from beyondtrust, specifically: privileged_remote_access, remote_support. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-40139? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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