CVE-2026-126792

medium

Description

A memory-safety flaw in the key-management request-building component of the library can lead to an out-of-bounds write on the heap. A fixed-size output buffer is used under an assumption about cryptographic key size that is never validated, so when the library is embedded by a caller that supplies its own cryptographic callback implementation, data larger than the buffer can be written past its end. Exploitation requires the ability to control the embedding application's in-process key-management provider configuration, a high-privilege position. The demonstrated impact is memory corruption resulting in abnormal termination of the client process.

References

https://jira.mongodb.org/browse/PYTHON-5999

https://jira.mongodb.org/browse/MONGOCRYPT-975

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-124805

Details

Source: Mitre, NVD

Published: 2026-11-13

Updated: 2026-11-13

Risk Information

CVSS v2

Base Score: 4.4

Vector: CVSS2#AV:L/AC:H/Au:M/C:N/I:P/A:C

Severity: Medium

CVSS v3

Base Score: 4.7

Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:H

Severity: Medium

CVSS v4

Base Score: 5.7

Vector: CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N

Severity: Medium

EPSS

EPSS: 0.001