CVE-2026-84970Heap over-read or silent misparse via 32-bit truncation of JSON length in BSON JSON parser
Updated under an hour ago ()
Does this affect you?
It affects MongoDB C++ Driver. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
A numeric truncation weakness exists in the JSON parsing component of the MongoDB C++ Driver's BSON library. An actor who controls the text that an embedding application hands to the library's public JSON parsing interface, when that text is very large, can cause the library to read memory beyond the supplied buffer and return it to the caller, to silently accept only part of the input as a complete document, or to terminate the process. No MongoDB server, credentials, or non-default configuration is required; the effect is confined to the process that uses the library.
- CVSS
- 6.2 MEDIUM (v3.1, CNA)CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H
- Weakness (CWE)
- CWE-681
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- mongodb
- NVD analysis
- Analyzed
- Record last updated
- Sep 3, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
MongoDB C++ Driver mongodb:c++_driver (from the name) | from 3.2.0 before 4.5.2 | CNA record |
mongodb c++_driver mongodb:c++_driver | from 3.2.0 before 4.5.2 | NVD |
References
- https://jira.mongodb.org/browse/CXX-3547vendor-advisory, issue-tracking
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.