USN-8123-1: Mbed TLS vulnerabilities

Publication date

25 March 2026

Overview

Several security issues were fixed in mbedtls.


Packages

  • mbedtls - Lightweight crypto and SSL/TLS library

Details

It was discovered that Mbed TLS incorrectly handled memory allocation
failures. A remote attacker could possibly use this issue to crash
the program. This issue only affected Ubuntu 18.04 LTS and Ubuntu
20.04 LTS. (CVE-2021-44732)

Jonathan Winzig discovered that Mbed TLS incorrectly handled crafted
inputs. A remote attacker could possibly use this issue to crash the
program, resulting in a denial of service. This issue only affected
Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS. (CVE-2024-23775)

It was discovered that Mbed TLS incorrectly handled the TLS
handshake. A remote attacker could possibly use this issue to
break the security guarantees of the TLS handshake.
(CVE-2025-27810)

Linh Le and Ngan Nguyen discovered that Mbed TLS incorrectly
documented the behavior of a function. Application code...

It was discovered that Mbed TLS incorrectly handled memory allocation
failures. A remote attacker could possibly use this issue to crash
the program. This issue only affected Ubuntu 18.04 LTS and Ubuntu
20.04 LTS. (CVE-2021-44732)

Jonathan Winzig discovered that Mbed TLS incorrectly handled crafted
inputs. A remote attacker could possibly use this issue to crash the
program, resulting in a denial of service. This issue only affected
Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS. (CVE-2024-23775)

It was discovered that Mbed TLS incorrectly handled the TLS
handshake. A remote attacker could possibly use this issue to
break the security guarantees of the TLS handshake.
(CVE-2025-27810)

Linh Le and Ngan Nguyen discovered that Mbed TLS incorrectly
documented the behavior of a function. Application code relying
on the documented behavior might be affected. A remote attacker
could possibly use this issue to execute arbitrary code.
(CVE-2025-47917)

Linh Le and Ngan Nguyen discovered that Mbed TLS incorrectly handled
crafted input. A remote attacker could possibly use this issue to
crash the program, resulting in a denial of service. (CVE-2025-48965)

It was discovered that Mbed TLS incorrectly handled a race condition.
An attacker could possibly use this issue to extract AES keys.
(CVE-2025-52496)

Linh Le and Ngan Nguyen discovered that Mbed TLS incorrectly handled
certain invalid input. A remote attacker could possibly use this
issue to crash the program, resulting in a denial of service.
(CVE-2025-52497)


Update instructions

In general, a standard system update will make all the necessary changes.

Learn more about how to get the fixes.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release Package Version
24.04 LTS noble libmbedcrypto7t64 –  2.28.8-1ubuntu0.1~esm1  
libmbedtls-dev –  2.28.8-1ubuntu0.1~esm1  
libmbedtls14t64 –  2.28.8-1ubuntu0.1~esm1  
libmbedx509-1t64 –  2.28.8-1ubuntu0.1~esm1  
22.04 LTS jammy libmbedcrypto7 –  2.28.0-1ubuntu0.1~esm1  
libmbedtls-dev –  2.28.0-1ubuntu0.1~esm1  
libmbedtls14 –  2.28.0-1ubuntu0.1~esm1  
libmbedx509-1 –  2.28.0-1ubuntu0.1~esm1  
20.04 LTS focal libmbedcrypto3 –  2.16.4-1ubuntu2+esm1  
libmbedtls-dev –  2.16.4-1ubuntu2+esm1  
libmbedtls12 –  2.16.4-1ubuntu2+esm1  
libmbedx509-0 –  2.16.4-1ubuntu2+esm1  
18.04 LTS bionic libmbedcrypto1 –  2.8.0-1ubuntu0.1~esm1  
libmbedtls-dev –  2.8.0-1ubuntu0.1~esm1  
libmbedtls10 –  2.8.0-1ubuntu0.1~esm1  
libmbedx509-0 –  2.8.0-1ubuntu0.1~esm1  

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