SB20261110305 - Fedora 43 update for mongo-c-driver



SB20261110305 - Fedora 43 update for mongo-c-driver

Published: November 10, 2026

Security Bulletin ID SB20261110305
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 75% Low 25%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 vulnerabilities.


1) NULL pointer dereference (CVE-ID: CVE-2026-120955)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to cause a denial of service by terminating applications using the MongoDB C Driver GridFS download API.

The vulnerability exists due to a null pointer dereference in mongoc_gridfs_bucket_download_to_stream() when an internal operation fails during file retrieval and stream operations continue without checking its result. A remote attacker can influence file download parameters to trigger application termination through malformed GridFS metadata.


2) Out-of-bounds read (CVE-ID: CVE-2026-120956)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: 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]


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.


3) Use of uninitialized resource (CVE-ID: CVE-2026-120684)

CWE-ID: CWE-908 - Use of Uninitialized Resource

CVSSv4: 6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote user to disclose sensitive application process memory, including credentials.

The vulnerability exists due to use of uninitialized memory in MongoDB C Driver's legacy GridFS file handling when an application appends to a file under attacker-arranged conditions. A remote user can manipulate files in shared storage with ordinary write access so that a subsequent application append stores uninitialized process memory as file content in records the user can read to obtain sensitive information.


4) Memory leak (CVE-ID: CVE-2026-120678)

CWE-ID: CWE-401 - Missing release of memory after effective lifetime

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to cause unbounded memory growth and a denial of service in applications using the MongoDB C Driver.

The vulnerability exists due to missing release of decompressed reply buffers in the MongoDB C Driver when parsing an OP_COMPRESSED response fails. A remote attacker can control the database endpoint a client connects to and repeatedly send compressed replies that fail to parse to exhaust application memory.


Remediation

Install update from vendor's website.