CVE-2026-114654 BSON output corruption via out-of-range binary subtype bypassing UUID and OldBinary guards
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-114654?
CVE-2026-114654 is a medium-severity vulnerability in MongoDB C# Driver, published on 22 Oct 2026.
Official description
A numeric-type conversion flaw in the BSON handling library of the MongoDB C# Driver allows an out-of-range binary subtype value supplied through untrusted textual input to bypass the library's binary-element integrity checks. When such a value is later encoded, it is narrowed to a smaller wire representation, producing binary elements that misdeclare their type or length. An unauthenticated party able to supply text parsed by an affected application can cause it to emit and persist malformed binary data, which subsequent readers either reject with an error or silently interpret as shorter than the data that was validated.
Weakness: CWE-681
Which versions are affected by CVE-2026-114654?
How do I fix CVE-2026-114654?
No fix has been published for CVE-2026-114654 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-114654 being exploited?
There is no known exploitation of CVE-2026-114654 in the wild and no public exploit code.
Sources
Also known as GHSA-5h2q-6c9r-7x25.