CVE-2025-66442

5.1 MEDIUM 0.3% exploit odds Fix listed Other

What it is

In Mbed TLS through 4.0.0, there is a compiler-induced timing side channel (in RSA and CBC/ECB decryption) that only occurs with LLVM's select-optimize feature. TF-PSA-Crypto through 1.0.0 is also affected.

At a glance

Exploitability: Can be exploited locally on the machine without logging in. High risk of data exposure.
Exploit odds: 0.3% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-04-01 20:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-11-04 22:10 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.3% in the next 30 days (EPSS).
Severity: 5.1 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-04-01 20:16 UTC
Last modified: 2026-11-04 22:10 UTC
Exploit probability: 0.3% · EPSS, next 30 days
Weakness: CWE-385
Record status: Analyzed

Affected

Arm Mbed Tls ≤ 4.0.0
Arm tf-psa-crypto ≤ 1.0.0

Attack profile CVSS 3.1 · 5.1

Attack vector: Local
Complexity: High
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Raw vector

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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2025-66442.md and follow it. Check whether this project is affected by CVE-2025-66442. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record