CVE-2026-25834 Security feature bypass in n/a

Medium 6.5 Published Updated

Attackers can force a downgrade to weaker cryptographic algorithms in Mbed TLS, compromising communication security.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2026-25834?

CVE-2026-25834 is a medium-severity vulnerability in n/a, published on 1 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Mbed TLS v3.3.0 up to 3.6.5 and 4.0.0 allows Algorithm Downgrade.

Weakness: CWE-327, CWE-295

Which versions are affected by CVE-2026-25834?

It affects 1 product.

Products include Trustedfirmware Mbed Tls.

How do I fix CVE-2026-25834?

Upgrade to a fixed version.

Is CVE-2026-25834 being exploited?

There is no known exploitation of CVE-2026-25834 in the wild and no public exploit code.

Sources

Also known as ALPINE-CVE-2026-25834, DEBIAN-CVE-2026-25834, GHSA-8j6f-944f-8jmj, UBUNTU-CVE-2026-25834.

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