==========================================================================
Ubuntu Security Notice USN-7973-1
January 23, 2026

cjson vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 25.10
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS

Summary:

Several security issues were fixed in cJSON.

Software Description:
- cjson: Ultralightweight JSON parser in ANSI C

Details:

It was discovered that cJSON incorrectly handled parsing large numbers. An
attacker could possibly use this issue to cause a denial of service.
(CVE-2023-26819)

It was discovered that cJSON may perform out-of-bounds read when processing
specially crafted JSON files using parse_object. An attacker could possibly
use this issue to expose sensitive information or crash the program.
(CVE-2023-53154)

It was discovered that cJSON incorrectly validated array indices in JSON
pointers, which could result in an out-of-bounds memory access. An attacker
could possibly use this issue to cause a denial of service, or execute
arbitrary code. (CVE-2025-57052)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 25.10
  libcjson1                       1.7.18-3.1ubuntu0.1

Ubuntu 24.04 LTS
  libcjson1                       1.7.17-1ubuntu0.1~esm3
                                  Available with Ubuntu Pro

Ubuntu 22.04 LTS
  libcjson1                       1.7.15-1ubuntu0.1

Ubuntu 20.04 LTS
  libcjson1                       1.7.10-1.1ubuntu0.1~esm1
                                  Available with Ubuntu Pro

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-7973-1
  CVE-2023-26819, CVE-2023-53154, CVE-2025-57052

Package Information:
  
  https://launchpad.net/ubuntu/+source/cjson/1.7.15-1ubuntu0.1