PatchaPalooza

CVE-2026-16554: Integer Overflow Leading to Heap Buffer Overflow in cJSON

CVE-2026-16554 is a vulnerability in Integer Overflow Leading to Heap Buffer Overflow in cJSON, rated Moderate by Microsoft. Microsoft has not reported exploitation in the wild. The EPSS model estimates a 0.37% probability of exploitation activity in the next 30 days, higher than 31% of all scored vulnerabilities. Microsoft released the fix on 6 August 2026, outside Patch Tuesday. It affects 2 products in 1 product family (Open Source Software).

Key facts

CVE ID
CVE-2026-16554
Severity
N/A
Microsoft severity
Moderate
Exploited in the wild
No
Publicly disclosed
No
Weakness
CWE-190
EPSS
0.37% (percentile 31%)
CISA KEV
Not listed
Released
Last updated
Patch Tuesday
July 2026 Patch Tuesday
Product families
Open Source Software

Affected products (2)

Open Source Software

ProductSecurity updateTypeFixed buildRestart
azl3 apparmor 3.1.7-1 on Azure Linux 3.0Release NotesSecurity Update
azl3 libglvnd 1.7.0-3 on Azure Linux 3.0Release NotesSecurity Update

NIST NVD data

NVD status
Analyzed
NVD CVSS
7.8 (HIGH)
NVD weakness
CWE-190
Published to NVD
NVD last modified

Affected configurations (CPE)

ProductVulnerable versions
cjson 1.7.19all listed versions

References

Revision history

VersionDateDescription
1.0Information published.
2.0Information published.
3.0Information published.
4.0Information published.

Sources