CVE-2026-126792: Memory Corruption (CVSS 4.7)

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.

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CVSS v3.1 Score

4.7

MEDIUM

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

Weakness Type (CWE)

CWE-787 Out-of-bounds Write

References

Other References

https://jira.mongodb.org/browse/MONGOCRYPT-975 https://jira.mongodb.org/browse/PYTHON-5999

Frequently Asked Questions

What is CVE-2026-126792? +

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. It has a CVSS v3.1 base score of 4.7 (MEDIUM).

How severe is CVE-2026-126792? +

CVE-2026-126792 has a CVSS v3.1 score of 4.7 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

How do I check if I'm vulnerable to CVE-2026-126792? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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