CVE-2026-120956: high-severity vulnerability in MongoDB C Driver
remote abort and memory disclosure from a malformed cursor.ns
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
18Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.1
The MongoDB C Driver does not validate the type or format of a namespace field returned by the server in a query response. A MongoDB endpoint that a client application connects to, without needing any credentials, can return a malformed value in that field. This causes the client application process to terminate, and can also cause the driver to read memory outside an allocated buffer and to send a small amount of the application's own uninitialized heap memory back to the endpoint in a follow-up command. The impact is limited to the process that embeds the driver.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
Affected products
MongoDB · C DriverRelated CVEs — MongoDB C Driver
In the same product, most dangerous first.
CVE-2026-96746HIGHHeap buffer overflow via mid-scan command list growth in client topology monitoringEPSS 0.4%CVE-2026-84963MEDIUMSilent field truncation via unchecked int cast of huge JSON string values in JSON-to-BSON parserEPSS 0.3%CVE-2026-84969MEDIUMHeap overflow via truncated base64 encoding of binary fields in length-limited JSON outputEPSS 0.3%CVE-2026-81524MEDIUMCross-tenant database retargeting via dot/NUL injection in namespace strings in the C DriverEPSS 0.3%CVE-2026-88036MEDIUMGridFS data disclosure and deletion via query-operator injection in file IDs in the MongoDB C DriverEPSS 0.3%CVE-2026-84964HIGHHeap corruption via OCSP request double free from crafted multi-URL certificate in TLS clientEPSS 0.3%