{"affected":[{"defaultStatus":"unaffected","product":"C Driver","source":"CNA: mongodb","vendor":"MongoDB","versions":[{"lessThanOrEqual":"2.5.7","status":"affected","version":"2.0.0","versionType":"semver"}]}],"cveId":"CVE-2026-120954","cwes":["CWE-190"],"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.","epss":null,"exploits":[],"kev":null,"metrics":[{"score":6.3,"severity":"medium","source":"CNA: mongodb","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","version":"4.0"},{"score":3.7,"severity":"low","source":"CNA: mongodb","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","version":"3.1"}],"modifiedAt":1793734933241,"publishedAt":1793731540025,"references":[{"source":"CNA: mongodb","tags":[],"url":"https://jira.mongodb.org/browse/CDRIVER-6420"}],"remediation":[],"revision":"91fa53c7e4cf4c3fc6f639c4c95ecfe3135d1840d9ea991c82925efd77852747","sources":[{"modifiedAt":1793734933241,"name":"CNA: mongodb","retrievedAt":1793736565251,"url":"https://www.cve.org/CVERecord?id=CVE-2026-120954"}],"ssvc":{"assessedAt":1793734924160,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"Silent element-count truncation via 32-bit bit-length overflow in packed-bit vector views","updatedAt":1793736565251}