CVE-2026-16554

MEDIUM
MEDIUM Priority: 0.02 BB Relevance: 45/100
Published: 2026-07-27 Modified: 2026-10-24 First seen: 2026-10-29 Status: active

Attack Surface

Low Complexity No Auth No Interaction

CVSS Vector Breakdown

AV: Local
AC: Low
PR: None
UI: None
S: X
AT: None
VC: None
VI: None
VA: Low

Description

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.

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
davegamble cjson 1.7.19

References & Advisories (4)

http://www.openwall.com/lists/oss-security/2026/07/30/26
Issue Tracking Mailing List Third Party Advisory

Bug Bounty Relevance

45 / 100
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

5.1 / 10.0 v4.0
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.37%
Raw Score 0.003670
Percentile 30.5%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00367
2026-10-28
0.00367

Intelligence Sources

nvd ref →