CVE-2026-120954
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.
- Score
- 6.3 medium
- Published
- 2026-11-03
- Links
- NVD · cve.org · Report wrong data
Matched ports (1)
| Port | Package | Version | Status | Maintainer |
|---|---|---|---|---|
| devel/mongo-c-driver | mongo-c-driver | 2.5.7 | unaddressed | ports@bsdserwis.com |
Template for a VuXML entry
Check the version numbers before you commit this entry. Some ports share an entry in the CVE database with another port, such as sqlite2 and sqlite3. The version shown here may then be one that never existed for this port.
Ranges per package from the CVE rows that match this port, in pkg notation with the port's epoch and revision, every bound checked with pkg; one range per epoch the port actually had. make newentry in security/vuxml creates the vid.
<vuln vid="FIXME (make newentry)">
<topic>mongo-c-driver -- FIXME</topic>
<affects>
<package>
<name>mongo-c-driver</name>
<range><ge>2.0.0</ge><le>2.5.7</le></range>
</package>
</affects>
<description>
<body xmlns="http://www.w3.org/1999/xhtml">
<p>CVE-2026-120954: 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.</p>
</body>
</description>
<references>
<cvename>CVE-2026-120954</cvename>
<url>https://nvd.nist.gov/vuln/detail/CVE-2026-120954</url>
</references>
<dates>
<discovery>2026-11-03</discovery>
<entry>2026-11-04</entry>
</dates>
</vuln>