Vulnerability-Lookup

GHSA-QV6Q-8G2J-W47G

Vulnerability from github – Published: 2026-07-27 09:31 – Updated: 2026-07-27 09:31

Details

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.

Severity

5.1 (Medium)


                  
                    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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-16554"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-190"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-27T09:16:37Z",
    "severity": "MODERATE"
  },
  "details": "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.\n\n\n\n\nBecause project creator contact attempts were unsuccessful, the vulnerability has only been confirmed in version 1.7.19 but may also affect other versions.",
  "id": "GHSA-qv6q-8g2j-w47g",
  "modified": "2026-07-27T09:31:27Z",
  "published": "2026-07-27T09:31:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-16554"
    },
    {
      "type": "WEB",
      "url": "https://cert.pl/en/posts/2026/07/CVE-2026-16554"
    },
    {
      "type": "WEB",
      "url": "https://github.com/DaveGamble/cJSON"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-16554 (GCVE-0-2026-16554)

Vulnerability from cvelistv5 – Published: 2026-07-27 08:40 – Updated: 2026-07-27 10:24 X_Open Source

Title

Integer Overflow Leading to Heap Buffer Overflow in cJSON

Summary

Severity

5.1 (Medium)


                        
                          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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-190 - Integer overflow or wraparound

Assigner

CERT-PL

References

2 references

URL	Tags
https://cert.pl/en/posts/2026/07/CVE-2026-16554	third-party-advisory
https://github.com/DaveGamble/cJSON	product

Impacted products

1 product

Vendor	Product	Version
DaveGamble	cJSON	Affected: 1.7.19 (semver)

Credits

Michał Majchrowicz (AFINE Team) Marcin Wyczechowski (AFINE Team)

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JSON

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                  },
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                "timestamp": "2026-07-27T10:24:13.881075Z",
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

GHSA-QV6Q-8G2J-W47G

CVE-2026-16554 (GCVE-0-2026-16554)

Tags

Sightings

Nomenclature