How severe is CVE-2026-40139?

No CVSS score has been assigned to CVE-2026-40139 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-40139?

Affected package information for CVE-2026-40139 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2026-40139?

No fixed release is recorded for CVE-2026-40139 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.

How do I detect CVE-2026-40139 in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate CVE-2026-40139 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2026-40139 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-40139 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-40139?

CVE-2026-40139 has an EPSS (Exploit Prediction Scoring System) score of 0.8%, placing it in the 54th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-40139?

CVE-2026-40139 is classified as Improper Authentication (CWE-287). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-40139 published, and has it been updated?

CVE-2026-40139 was published on July 6, 2026 and was last updated on July 7, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2026-40139: Auth Bypass

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-40139.

EPSS Exploitation Probability

via FIRST.org ↗

0.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs54th percentile — riskier than 54% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

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.

Affected Products

2 products · 2 configurations

Application

privileged remote accessbeyondtrust

< 25.3.3

range

Application

remote supportbeyondtrust

< 25.3.3

range

Detection & mitigation playbook

Vulnerability

Detect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
No fixed release is recorded for CVE-2026-40139 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

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.

O3 Security · Impact-Aware SCA

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CVE-2026-40139