CVE-2026-16554
Published:July 27, 2026
Updated:August 06, 2026
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.
Related Resources (6)
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Contact UsCVSS v4
Base Score:
5.1
Attack Vector
LOCAL
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
LOW
Subsequent System Confidentiality
LOW
Subsequent System Integrity
LOW
Subsequent System Availability
LOW
CVSS v3
Base Score:
4.3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Weakness Type (CWE)
Integer Overflow or Wraparound
EPSS
Base Score:
0.29