Use of a Broken or Risky Cryptographic Algorithm The advisory has been revoked - it doesn't affect any version of package mbedtls  (opens in a new tab)


Threat Intelligence

EPSS
0.16% (7th percentile)

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  • Snyk IDSNYK-UBUNTU1604-MBEDTLS-3235652
  • published21 Mar 2026
  • disclosed17 Jan 2023

Introduced: 17 Jan 2023

CVE-2021-36647  (opens in a new tab)
CWE-327  (opens in a new tab)

Amendment

The Ubuntu security team deemed this advisory irrelevant for Ubuntu:16.04.

NVD Description

Note: Versions mentioned in the description apply only to the upstream mbedtls package and not the mbedtls package as distributed by Ubuntu.

Use of a Broken or Risky Cryptographic Algorithm in the function mbedtls_mpi_exp_mod() in lignum.c in Mbed TLS Mbed TLS all versions before 3.0.0, 2.27.0 or 2.16.11 allows attackers with access to precise enough timing and memory access information (typically an untrusted operating system attacking a secure enclave such as SGX or the TrustZone secure world) to recover the private keys used in RSA.