Vulnerability · CVE-2026-114654
BSON output corruption via out-of-range binary subtype bypassing UUID and OldBinary guards
Published Oct 22, 2026 · catalog updated Oct 22, 2026 · MongoDB C# Driver
Open the advisory
Exploitation likelihood is not on this record for CVE-2026-114654. A missing EPSS score is not a low risk. Compare MongoDB C# Driver with the linked advisory before you change production.
Gaps on this record
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- EPSS is missing. A missing score is not a low risk.
- Severity
- Medium6.9
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- Not in the current FIRST EPSS dataset
- Remediation
- Advisory link
- Affected products
- vendor MongoDB C# Driver
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.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- vendor MongoDB C# Driverversion unspecified
How to fix CVE-2026-114654
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
Exploitation likelihood is not on this record for CVE-2026-114654. A missing EPSS score is not a low risk. Compare MongoDB C# Driver with the linked advisory before you change production.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-681. EPSS is absent from the current FIRST dataset. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Oct 22, 2026 · CVE.org
Updated
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
Oct 23, 2026 · BSI CERT-Bund
Detected
CVE-2026-114654 is listed by MongoDB C# Treiber: Mehrere Schwachstellen.
Sources
- BSI CERT-BundGovernment advisoryCVE-2026-114654
MongoDB C# Treiber: Mehrere Schwachstellen
wid.cert-bund.de - CVE.orgVulnerability recordCVE-2026-114654
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
cve.org
References
Freshness
Last verified in this catalog Oct 23, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.