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.

Published: 2024-04-03 Last update: 2026-06-05 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-28836 is rated Moderate Risk (41/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.32%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-28836

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-23 0.11% 0.32% +0.20%
2 2026-01-05 0.33% 0.11% -0.22%
3 2025-11-21 — 0.33% —

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-28836

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.5 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2024-28836

OS Trackers for CVE-2024-28836

vendor priority summary link
debian unimportant CVE-2024-28836 unimportant priority: Debian including 1 source packages (mbedtls), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2024-28836
ubuntu medium CVE-2024-28836 medium priority: Ubuntu including 1 source packages (mbedtls), 10 status rows across 10 suites (bionic, focal, jammy, mantic, noble, oracular, plucky, questing, upstream, xenial): not-affected 7, ignored 2, released 1. https://ubuntu.com/security/CVE-2024-28836

Affected software / configurations for CVE-2024-28836

Vendor Product Version Raw CPE
trustedfirmware mbed_tls >= 3.5.0, < 3.6.0 cpe:2.3:a:trustedfirmware:mbed_tls:*:*:*:*:*:*:*:*

References for CVE-2024-28836

cvelogic Threat Intelligence