{"schemaVersion":3,"id":"CVE-2026-16554","aliases":["UBUNTU-CVE-2026-16554","DEBIAN-CVE-2026-16554"],"status":"published","duplicateOf":null,"title":null,"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.\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.","dates":{"published":"2026-07-27T08:40:17.183Z","modified":"2026-07-31T13:34:05.448Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":7.8,"severity":"high","version":"3.1","versionLabel":"v3.1","source":"NVD","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","computed":false,"selection":"backend-summary"},"metrics":[{"version":"4.0","versionLabel":"v4.0","source":"CVE.org","score":5.1,"severity":"medium","vector":"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","exploitability":null,"impact":null,"computed":false},{"version":"4.0","versionLabel":"v4.0","source":"OSV · Ubuntu","score":5.1,"severity":"medium","vector":"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","exploitability":null,"impact":null,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · 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Overflow or Wraparound","description":"The product performs a calculation that can\n         produce an integer overflow or wraparound when the logic\n         assumes that the resulting value will always be larger than\n         the original value. This occurs when an integer value is\n         incremented to a value that is too large to store in the\n         associated representation. When this occurs, the value may\n         become a very small or negative number.","type":"weakness","status":"Stable","abstraction":"Base","likelihoodOfExploit":"Medium","url":"https://cwe.mitre.org/data/definitions/190.html"}],"affected":[{"vendor":"davegamble","product":"cjson","name":"cjson","label":"cjson","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"1.7.19","noFixRecorded":false,"fixedIn":null}],"versionsText":"1.7.19","eol":null,"hubHref":"/vendor/davegamble/cjson"},{"vendor":"debian","product":"cjson","name":"cjson","label":"cjson","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/cjson","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"cjson","name":"cjson","label":"cjson","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/cjson","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null}],"affectedCount":3,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://cert.pl/en/posts/2026/07/CVE-2026-16554","label":"cert.pl/en/posts/2026/07/CVE-2026-16554","hostname":"cert.pl","tags":["Third Party Advisory","REPORT"]},{"url":"https://github.com/DaveGamble/cJSON","label":"github.com/DaveGamble/cJSON","hostname":"github.com","tags":["Product","REPORT"]},{"url":"http://www.openwall.com/lists/oss-security/2026/07/30/26","label":"www.openwall.com/lists/oss-security/2026/07/30/26","hostname":"www.openwall.com","tags":["Issue Tracking","Mailing List","Third Party Advisory"]},{"url":"http://www.openwall.com/lists/oss-security/2026/07/31/4","label":"www.openwall.com/lists/oss-security/2026/07/31/4","hostname":"www.openwall.com","tags":["Mailing List","Third Party Advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-16554","label":"ubuntu.com/security/CVE-2026-16554","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-16554","label":"www.cve.org/CVERecord?id=CVE-2026-16554","hostname":"www.cve.org","tags":["REPORT"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-16554","label":"security-tracker.debian.org/tracker/CVE-2026-16554","hostname":"security-tracker.debian.org","tags":["Advisory"]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2026-07-27T08:40:17.183Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-07-31T13:34:05.448Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":31,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-21T00:24:07.111Z","stale":false,"partial":false}}