Out-of-bounds read in MongoDB driver for C - CVE-2026-120956
Published: November 10, 2026
Vulnerability identifier: #VU164410
CSH Severity: Medium
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-120956
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to terminate the client application process and disclose a small amount of its uninitialized heap memory.
The vulnerability exists due to insufficient namespace validation and an out-of-bounds read in the MongoDB C Driver when processing server query responses containing malformed cursor.ns values. A remote attacker can return a malformed namespace from an endpoint the client connects to, causing process termination or disclosure of application memory to that endpoint through a follow-up command.
Affected software
MongoDB driver for C
Fedora
mongo-c-driver
Fedora
mongo-c-driver
How to mitigate CVE-2026-120956
Install security update from vendor's website.
MongoDB driver for C - addressed in versions 1.30.15, 2.5.8
mongo-c-driver - addressed in versions 1.30.15-1.el8, 1.30.15-1.el9, 1.30.15-1.el10_2, 1.30.15-1.fc43, 1.30.15-1.fc44, 2.5.8-1.el10_3, 2.5.8-1.el10_4, 2.5.8-1.fc45
mongo-c-driver - addressed in versions 1.30.15-1.el8, 1.30.15-1.el9, 1.30.15-1.el10_2, 1.30.15-1.fc43, 1.30.15-1.fc44, 2.5.8-1.el10_3, 2.5.8-1.el10_4, 2.5.8-1.fc45
External References
Related Security Bulletins
- Multiple vulnerabilities in MongoDB driver for C
- Fedora EPEL 9 update for mongo-c-driver
- Fedora EPEL 8 update for mongo-c-driver
- Fedora EPEL 10.2 update for mongo-c-driver
- Fedora 43 update for mongo-c-driver
- Fedora 44 update for mongo-c-driver
- Fedora EPEL 10.3 update for mongo-c-driver
- Fedora EPEL 10.4 update for mongo-c-driver
- Fedora 45 update for mongo-c-driver