CVE-2026-106431
An actor who can influence the size of documents serialized by an embedding application can corrupt adjacent process memory or terminate the process.
Does this matter?
Lower severity and a low EPSS score (0.10%). Track it; it rarely justifies an emergency change on its own.
Description
An off-by-one error in the BSON bulk document writer in the MongoDB C Driver can write one zero byte immediately past a heap allocation when a document ends at a specific buffer boundary. An actor who can influence the size of documents serialized by an embedding application can corrupt adjacent process memory or terminate the process. Reaching this issue requires the application to use the BSON bulk-writer API and produce a precise cumulative document size.
- CVSS 4.0
- 5.9 MEDIUMCVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.10% probability · 1th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-787
- Source
- cna@mongodb.com
EPSS moved from 0.1% on 9 October 2026 to 0.1% on 26 October 2026.
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.