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Public proof of conceptFix available

CVE-2026-67216

A public proof of concept exists; no exploitation attested.

  • Published2026-07-29
  • WeaknessCWE-407

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

cJSON through 1.7.19 contains an inefficient algorithmic complexity flaw in cJSON_Compare(). When comparing objects, the function recurses into each shared subtree twice, once in each direction, with no depth guard, making the running time exponential in nesting depth. A small, deeply nested document of a few hundred bytes (depth around 40) compared for equality consumes hours of CPU, and the cost roughly doubles with each additional level of nesting. An application that calls cJSON_Compare() on attacker-influenced JSON that is structurally equal to a reference document is exposed to a denial-of-service condition.

Timeline

dates in UTC
  1. 2026-07-2914:16CVE publishedNVD

Versions per branch

NVD
Davegamble cjson
BranchAffectedFixed in
1.7≤ 1.7.19no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As VulnCheck, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • DaveGamble cJSONother versions: affected
    Affected
    • ≤ 1.7.19no fix statedsemver

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-07-29

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • apparmorAzure Linux:3all versions · no fixed version listed
  • cjsonUbuntu:Pro:24.04:LTSall versions · no fixed version listedand 1 other package
  • cjsonUbuntu:Pro:22.04:LTSall versions · no fixed version listedand 1 other package
  • cjsonUbuntu:Pro:20.04:LTSall versions · no fixed version listedand 1 other package
  • cjsonUbuntu:26.10all versions · no fixed version listedand 3 other packages
  • cjsonUbuntu:26.04:LTSall versions · no fixed version listedand 3 other packages
  • cjsonRoot:Alpine:3.23all versions · fixed in 1.7.19-r10071and 1 other package
  • cjsonRoot:Alpine:3.23all versions · fixed in 1.7.19-r10072and 1 other package

15 more package ranges on OSV.dev

Vendor advisories

  • CVE-2026-67216 Red Hat Product Security

    cJSON: Denial of Service due to inefficient JSON object comparison

Full record on NVD

Fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

  • CISA-ADPSSVC decisionpoc2026-07-30
  • CNACVSS 4.08.2known since 2026-10-24
  • CNACVSS 3.15.9known since 2026-10-24
  • NVDCVSS 3.17.5read 2026-10-24
  • CNAweakness (CWE)CWE-407known since 2026-10-24
  • FIRST EPSSEPSS score0.6 %2026-11-08
  • OSVaffected packages—
  • GitHub Advisoriesadvisory—

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 4.0 vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/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
Published
2026-07-29
Last Modified
2026-10-23
NVD status
Analyzed
GitHub Advisory
GHSA-ff2v-f99f-wm3f

Frequently asked questions

What is CVE-2026-67216?

cJSON through 1.7.19 contains an inefficient algorithmic complexity flaw in cJSON_Compare(). When comparing objects, the function recurses into each shared subtree twice, once in each direction, with no depth guard, making the running time exponential in nesting depth. A small, deeply nested document of a few hundred bytes (depth around 40) compared for equality consumes hours of CPU, and the cost roughly doubles with each additional level of nesting. An application that calls cJSON_Compare() on attacker-influenced JSON that is structurally equal to a reference document is exposed to a denial-of-service condition.

Is CVE-2026-67216 actively exploited?

A proof-of-concept exploit exists for CVE-2026-67216, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2026-67216?

CVE-2026-67216 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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Sources for this record