Vulnerability · Published May 20, 2026 · Assigned by mongodb

CVE-2026-9100Heap memory out of bounds read and crash in C Driver legacy GridFS file reader

Medium 5.9

In plain English

A medium-severity security flaw in C Driver from MongoDB, Inc.. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 23% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.9Medium

Exploit odds (30 days)0.3%top 77.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

The MongoDB C Driver's legacy GridFS API accepts malformed file metadata from the database without adequate validation. Crafted documents in a GridFS collection may cause any application that reads those files via the legacy API to either crash (via a division-by-zero) or silently leak process memory contents (via an out-of-bounds read).

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Alpine:v3.24	mongo-c-driver	1.30.14-r0	ALPINE-CVE-2026-9100
Debian:12	mongo-c-driver	1.23.1-1+deb12u3	DEBIAN-CVE-2026-9100
Debian:13	mongo-c-driver	1.30.4-1+deb13u2	DEBIAN-CVE-2026-9100
Debian:14	mongo-c-driver	2.2.4-1	DEBIAN-CVE-2026-9100
Ubuntu:25.10	mongo-c-driver	no fix listed	UBUNTU-CVE-2026-9100
Ubuntu:26.04:LTS	mongo-c-driver	no fix listed	UBUNTU-CVE-2026-9100
Ubuntu:26.10	mongo-c-driver	no fix listed	UBUNTU-CVE-2026-9100

Affected products (as reported)

Vendor	Product	Versions
MongoDB, Inc.	C Driver	1.0 – before 1.30.82.0 – before 2.2.4

Weakness: CWE-1285 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:H

References

https://jira.mongodb.org/browse/CDRIVER-6281 issue-tracking