Covert Timing Channel in mbed TLS - CVE-2025-54764
Published: October 17, 2025
Vulnerability identifier: #VU117337
CSH Severity: Medium
CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2025-54764
CWE-ID: CWE-385
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to decrypt data.
The vulnerability exists due to side channel in RSA key generation and operations when the following functions are used: mbedtls_rsa_gen_key(), psa_generate_key*(), mbedtls_rsa_complete(), mbedtls_mpi_inv_mod(). An attacker can fully recover the RSA private key.
Affected software
mbed TLS
Fedora
mbedtls
Fedora
mbedtls
How to mitigate CVE-2025-54764
Install updates from vendor's website.
mbed TLS - update to 3.6.5
mbedtls - addressed in versions 3.6.4-2.el10_2, 3.6.5-1.el10_0, 3.6.5-1.el10_1, 3.6.5-1.el10_2, 3.6.5-1.fc42, 3.6.5-1.fc43
mbedtls - addressed in versions 3.6.4-2.el10_2, 3.6.5-1.el10_0, 3.6.5-1.el10_1, 3.6.5-1.el10_2, 3.6.5-1.fc42, 3.6.5-1.fc43