SB2026033149 - Ubuntu update for mbedtls
Published: March 31, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 7 secuirty vulnerabilities.
1) Double Free (CVE-ID: CVE-2021-44732)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error. A remote attacker can send a specially crafted request to the application, trigger a double free error and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
2) Integer overflow (CVE-ID: CVE-2024-23775)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to integer overflow in mbedtls_x509_set_extension(). A remote attacker can pass specially crafted data to the application, trigger an integer overflow and perform a denial of service (DoS) attack.
3) Improper authentication (CVE-ID: CVE-2025-27810)
The vulnerability allows a remote attacker to bypass authentication process.
The vulnerability exists due to an error when handling memory allocations during TLS handshake. A remote attacker with ability to trigger memory allocation failures or cryptographic hardware failures can impersonate a legitimate peer by tampering with handshake messages.
4) Use-after-free (CVE-ID: CVE-2025-47917)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error within the mbedtls_x509_string_to_names() function. A remote attacker can send specially crafted data to the application, trigger a use-after-free error and execute arbitrary code on the system.
Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.
5) NULL pointer dereference (CVE-ID: CVE-2025-48965)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error within the mbedtls_asn1_store_named_data() function. A remote attacker can pass specially crafted data to the application and perform a denial of service (DoS) attack.
6) Race condition (CVE-ID: CVE-2025-52496)
The vulnerability allows a remote attacker to perform MitM attack.
The vulnerability exists due to a race condition on x86 and amd64 systems that have the AESNI instruction, as it can be used for AES encryption and decryption. A remote attacker can extract AES keys from multithreaded programs and use them to decrypt traffic.
7) Out-of-bounds read (CVE-ID: CVE-2025-52497)
The vulnerability allows a remote attacker to gain access to potentially sensitive information.
The vulnerability exists due to a boundary condition when parsing invalid PEM-encrypted material in mbedtls_pk_parse_key(), mbedtls_pk_parse_keyfile() and mbedtls_pem_read_buffer() functions. A remote attacker can pass specially crafted data to the application, trigger an out-of-bounds read error and read contents of memory on the system or perform a denial of service attack.
Remediation
Install update from vendor's website.