CVE-2024-28836: mbed tls — Fix

Description

An issue was discovered in Mbed TLS 3.5.x before 3.6.0. When negotiating the TLS version on the server side, it can fall back to the TLS 1.2 implementation of the protocol if it is disabled. If the TLS 1.2 implementation was disabled at build time, a TLS 1.2 client could put a TLS 1.3-only server into an infinite loop processing a TLS 1.2 ClientHello, resulting in a denial of service. If the TLS 1.2 implementation was disabled at runtime, a TLS 1.2 client can successfully establish a TLS 1.2 connection with the server.

Is your site exposed to CVE-2024-28836?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

5.4

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Weakness Type (CWE)

CWE-835 CWE-835

Affected Products

Vendor	Product	Versions
arm	mbed_tls	3.5.0 — 3.6.0

References

Advisories & Patches

https://mbed-tls.readthedocs.io/en/latest/tech-updates/security-advisories/ https://mbed-tls.readthedocs.io/en/latest/tech-updates/security-advisories/

Other References

https://github.com/Mbed-TLS/mbedtls/releases/tag/v3.6.0 https://github.com/Mbed-TLS/mbedtls/releases/tag/v3.6.0

Frequently Asked Questions

What is CVE-2024-28836? +

An issue was discovered in Mbed TLS 3.5.x before 3.6.0. When negotiating the TLS version on the server side, it can fall back to the TLS 1.2 implementation of the protocol if it is disabled. If the TLS 1.2 implementation was disabled at build time, a TLS 1.2 client could put a TLS 1.3-only server into an infinite loop processing a TLS 1.2 ClientHello, resulting in a denial of service. If the TLS 1.2 implementation was disabled at runtime, a TLS 1.2 client can successfully establish a TLS 1.2 connection with the server. It has a CVSS v3.1 base score of 5.4 (MEDIUM).

How severe is CVE-2024-28836? +

CVE-2024-28836 has a CVSS v3.1 score of 5.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2024-28836? +

CVE-2024-28836 affects products from arm, specifically: mbed_tls. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2024-28836? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2025-27497

OpenDJ is an LDAPv3 compliant directory service. OpenDJ prior to 4.9.3 contains a denial-of-service (DoS) vulnerability that causes the server …

CVE-2025-29776

Azle is a WebAssembly runtime for TypeScript and JavaScript on ICP. Calling `setTimer` in Azle versions `0.27.0`, `0.28.0`, and `0.29.0` …

CVE-2025-32029

ts-asn1-der is a collection of utility classes to encode ASN.1 data following DER rule. Incorrect number DER encoding can lead …

CVE-2024-8088

There is a HIGH severity vulnerability affecting the CPython "zipfile" module affecting "zipfile.Path". Note that the more common API "zipfile.ZipFile" …

CVE-2026-63570

Loop with unreachable exit condition in Pkcs12Store.GetCertificateChain in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker …

CVE-2026-93925

Stack-based buffer overflow, Incorrect bitwise shift of integer vulnerability in Apache Thrift C++ THeaderProtocol. This issue affects Apache Thrift: before …

CVE-2024-28836