CVE-2025-66442
Mbed TLS through 4.0.0 vulnerability
Mbed · In Mbed TLS through 4.0.0, there is a compiler-induced timing side channel (in RSA and CBC/ECB decryption) that only occurs with LLVM's select-optimize feature. TF-PSA-Crypto through 1.0.0 is also affected.
MSRC advisory May 19, 2026
Alert details
- Source feed
- Microsoft MSRC
- CVE ID
- CVE-2025-66442
- Affected products
- In Mbed TLS through 4.0.0, there is a compiler-induced timing side channel (in RSA and CBC/ECB decryption) that only occurs with LLVM's select-optimize feature. TF-PSA-Crypto through 1.0.0 is also affected. · In In Mbed TLS through 4.0.0, there is a compiler-induced timing side channel (in RSA and CBC/ECB decryption) that only occurs with LLVM's select-optimize feature. TF-PSA-Crypto through 1.0.0 is also affected. · In
What happened
Information published.
What it means for your business
In In Mbed TLS through 4.0.0, there is a compiler-induced timing side channel (in RSA and CBC/ECB decryption) that only occurs with LLVM's select-optimize feature. TF-PSA-Crypto through 1.0.0 is also affected. (CVE-2025-66442) was added to Microsoft’s security update guidance. Information published. PremierePC tracks MSRC advisories for Upstate SC businesses — patch or open a ticket if you need help verifying exposure.
EPSS probability
0.27%
Sources
Related briefs
Microsoft Partner Center Elevation of Privilege vulnerability
Microsoft Partner Center Elevation of Privilege vulnerability (CVE-2026-96207) was added to Microsoft’s security update guidance. <p>Improper certificate validation in Microsoft Partner Center allows an unauthorized attacker to elevate privileges over a network.</p> If you need help checking exposure, call (864) 335-9223.
Microsoft Bookings Elevation of Privilege vulnerability
Microsoft Bookings Elevation of Privilege vulnerability (CVE-2026-94510) was added to Microsoft’s security update guidance. <p>Authorization bypass through user-controlled key in Microsoft Bookings allows an unauthorized attacker to elevate privileges over a network.</p> If you need help checking exposure, call (864) 335-9223.
Microsoft Dataverse Remote Code Execution vulnerability
Microsoft Dataverse Remote Code Execution vulnerability (CVE-2026-88131) was added to Microsoft’s security update guidance. <p>Deserialization of untrusted data in Microsoft Dataverse allows an unauthorized attacker to execute code over a network.</p> If you need help checking exposure, call (864) 335-9223.
Azure Event Grid Spoofing vulnerability
Azure Event Grid Spoofing vulnerability (CVE-2026-83947) was added to Microsoft’s security update guidance. <p>Missing authorization in Azure Event Grid allows an authorized attacker to perform spoofing over a network.</p> If you need help checking exposure, call (864) 335-9223.
Need help patching?
PremierePC monitors KEV alerts for managed clients and helps teams prioritize remediation before attackers do.