An issue was discovered in Mbed TLS 3.5.1. There is persistent handshake denial if a client sends a TLS 1.3 ClientHello without extensions.

CVE-2026-25835 high · 7.7

Mbed TLS before 3.6.6 and TF-PSA-Crypto before 1.1.0 misuse seeds in a Pseudo-Random Number Generator (PRNG).

CVE-2025-49087 medium · 4.0

In Mbed TLS 3.6.1 through 3.6.3 before 3.6.4, a timing discrepancy in block cipher padding removal allows an attacker to recover the plaintext when PKCS#7 padding mode is used.

CVE-2025-49600 medium · 4.9

In MbedTLS 3.3.0 before 3.6.4, mbedtls_lms_verify may accept invalid signatures if hash computation fails and internal errors go unchecked, enabling LMS (Leighton-Micali Signature)

CVE-2025-49601 medium · 4.8

In MbedTLS 3.3.0 before 3.6.4, mbedtls_lms_import_public_key does not check that the input buffer is at least 4 bytes before reading a 32-bit field, allowing a possible out-of-boun

CVE-2025-27809 medium · 5.4

Mbed TLS before 2.28.10 and 3.x before 3.6.3, on the client side, accepts servers that have trusted certificates for arbitrary hostnames unless the TLS client application calls mbe

CVE-2025-27810 medium · 5.4

Mbed TLS before 2.28.10 and 3.x before 3.6.3, in some cases of failed memory allocation or hardware errors, uses uninitialized stack memory to compose the TLS Finished message, pot