CVE-2026-120954: MongoDB C Driver · Integer Overflow or Wraparound
Affects MongoDB C DriverSource CVE Database V5
Not known to be exploited · CVSS 6.3 Medium.
Data as of 3 Nov 2026, 19:58 UTC
Thin evidence
One scorer or none| CNA (mongodb) | CVSS 4.0 | 6.3 |
|---|---|---|
| CNA (mongodb) | CVSS 3.1 | 3.7 |
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 3 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| MongoDBC Driver | Affected
| Fixed in– |
AI-suggested
Until a fix is available, avoid parsing untrusted BSON data on 32-bit builds of the MongoDB C Driver or implement application-level validation to detect and reject oversized element counts in BSON binary vector types.
Description
A weakness in the BSON library's handling of a specialized binary vector data type allows an arithmetic wraparound when computing the number of elements described by an oversized attacker-supplied value. On builds where the platform word size is 32 bits, an application that parses untrusted BSON data can be made to process only a small fraction of the supplied elements while the operation reports success, producing results that disagree with byte-oriented accessors and with 64-bit builds of the same library. No authentication or user interaction is required beyond getting the application to parse the data. The impact is limited to data integrity; memory safety is not affected and no information is disclosed.