CVE-2026-106434 Unrecognized payload acceptance in explicit decryption in MongoDB libmongocrypt
Attackers can inject unrecognized payloads into encrypted fields, causing applications to process them as plaintext, potentially leading to data exposure or logic errors.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-106434?
CVE-2026-106434 is a medium-severity vulnerability in MongoDB libmongocrypt, published on 8 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
The explicit decryption component of MongoDB libmongocrypt can return an unrecognized encrypted payload unchanged instead of returning a decryption error. An actor who can modify stored encrypted fields, such as a database writer, server, or network intermediary, can cause an affected application to process the supplied bytes as decrypted plaintext.
Weakness: CWE-354
Which versions are affected by CVE-2026-106434?
How do I fix CVE-2026-106434?
Upgrade to a fixed version.
Is CVE-2026-106434 being exploited?
There is no known exploitation of CVE-2026-106434 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-106434, UBUNTU-CVE-2026-106434.