USN-7973-1: cJSON vulnerabilities

Publication date

23 January 2026

Overview

Several security issues were fixed in cJSON.


Packages

  • 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)

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

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

Learn more about how to get the fixes.

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

Ubuntu Release Package Version
25.10 questing libcjson1 –  1.7.18-3.1ubuntu0.1
24.04 LTS noble libcjson1 –  1.7.17-1ubuntu0.1~esm3  
22.04 LTS jammy libcjson1 –  1.7.15-1ubuntu0.1
20.04 LTS focal libcjson1 –  1.7.10-1.1ubuntu0.1~esm1  

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