Covert Timing Channel in mbed TLS - CVE-2025-59438
Published: October 17, 2025
Vulnerability identifier: #VU117336
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2025-59438
CWE-ID: CWE-385
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: ARM
Affected software:
mbed TLS
mbed TLS
Detailed vulnerability description
The vulnerability allows an attacker to perform padding oracle attack.
The vulnerability exists due to padding oracle through timing of cipher error reporting. An attacker can recover plain texts encrypted with CBC-PKCS7 or other symmetric encryption mode using padding when it is decrypted through the PSA API.
How to mitigate CVE-2025-59438
Install updates from vendor's website.