CVE-2026-16554
cJSON library is vulnerable to an integer overflow in the print_string_ptr() function in cJSON.c on 32-bit platforms. The escape_characters counter, a 32-bit size_t, can wrap around when processing strings containing approximately 858,993,460 or more control characters, causing the output buffer to be allocated based on an underestimated length. When cJSON_PrintBuffered() is used with a pre-allocated buffer, the subsequent write loop overflows the heap allocation. An attacker supplying a crafted JSON string to an application using cJSON on a 32-bit platform can cause a heap buffer overflow, potentially leading to remote code execution, information disclosure, or denial of service. Because project creator contact attempts were unsuccessful, the vulnerability has only been confirmed in version 1.7.19 but may also affect other versions.
Matched ports (1)
| Port | Package | Version | Status | Maintainer |
|---|---|---|---|---|
| devel/libcjson | libcjson | 1.7.19_1 | unaddressed | sunpoet@FreeBSD.org |
Template for a VuXML entry
Range taken from the CVE record, check it before committing. make newentry in security/vuxml creates the vid.
<vuln vid="FIXME (make newentry)">
<topic>FIXME -- FIXME</topic>
<affects>
<package>
<name>libcjson</name>
<range><lt>FIXME</lt></range>
</package>
</affects>
<description>
<body xmlns="http://www.w3.org/1999/xhtml">
<p>cJSON library is vulnerable to an integer overflow in the
print_string_ptr() function in cJSON.c on 32-bit platforms. The
escape_characters counter, a 32-bit size_t, can wrap around when
processing strings containing approximately 858,993,460 or more
control characters, causing the output buffer to be allocated based on
an underestimated length. When cJSON_PrintBuffered() is used with a
pre-allocated buffer, the subsequent write loop overflows the heap
allocation. An attacker supplying a crafted JSON string to an
application using cJSON on a 32-bit platform can cause a heap buffer
overflow, potentially leading to remote code execution, information
disclosure, or denial of service.
Because project creator contact
attempts were unsuccessful, the vulnerability has only been confirmed
in version 1.7.19 but may also affect other versions.</p>
</body>
</description>
<references>
<cvename>CVE-2026-16554</cvename>
<url>https://nvd.nist.gov/vuln/detail/CVE-2026-16554</url>
</references>
<dates>
<discovery>2026-07-27</discovery>
<entry>2026-10-26</entry>
</dates>
</vuln>