CVE-2026-67216
cJSON cJSON_Compare Exponential Complexity Denial of Service
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
8.2
cJSON cJSON_Compare Exponential Complexity Denial of Service
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.
- Record
CVE-2026-67216- CVSS 4.0
- 8.2 High
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 - CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-407
- Updated
- 2026-11-02
EUVDEUVD-2026-50328
8.2
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.
- Record
EUVD-2026-50328- CVSS 4.0
- 8.2 High
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-ff2v-f99f-wm3f
8.2
cJSON through 1.7.19 contains an inefficient algorithmic complexity flaw in cJSON_Compare(). When...
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.
- Record
GHSA-ff2v-f99f-wm3f- CVSS 4.0
- 8.2 High
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 - CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-407
- Updated
- 2026-11-02
NVD
8.2
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.
- Record
CVE-2026-67216- CVSS 4.0
- 8.2 High
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 - CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-407
- Updated
- 2026-11-02
OSV
8.2
cJSON cJSON_Compare Exponential Complexity Denial of Service
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.
- Record
CVE-2026-67216- CVSS 4.0
- 8.2 High
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 - Weakness
- CWE-407
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-67216
7.5
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.
- Record
DEBIAN-CVE-2026-67216- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Show 4 moreShow less
OSVUBUNTU-CVE-2026-67216
8.2
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.
- Record
UBUNTU-CVE-2026-67216- CVSS 4.0
- 8.2 High
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 - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVAZL-94407 No score
CVE-2026-67216 affecting package apparmor 3.1.7-1
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.
- Record
AZL-94407- Updated
- 2026-11-05
OSVROOT-OS-ALPINE-321-CVE-2026-67216 No score
CVE-2026-67216 in cjson - Patched by Root
Root has patched CVE-2026-67216 in the cjson package for Root:Alpine:3.21. Multiple fixed versions available.
- Record
ROOT-OS-ALPINE-321-CVE-2026-67216- Updated
- 2026-11-02
OSVROOT-OS-ALPINE-323-CVE-2026-67216 No score
CVE-2026-67216 in cjson - Patched by Root
Root has patched CVE-2026-67216 in the cjson package for Root:Alpine:3.23. Multiple fixed versions available.
- Record
ROOT-OS-ALPINE-323-CVE-2026-67216- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
apparmorAzure Linux:3 |
through 3.1.7-1 | None known |
cjsonDebian:12 |
All versions, plus listed versions 1.7.15-11.7.15-1+deb12u11.7.15-1+deb12u21.7.15-1+deb12u31.7.15-1+deb12u4 Show 11 moreShow less1.7.16-11.7.16-21.7.17-11.7.17-21.7.18-11.7.18-21.7.18-31.7.18-3.11.7.18-41.7.19-11.7.19-2 |
None known |
cjsonDebian:13 |
All versions, plus listed versions 1.7.18-3.11.7.18-3.1+deb13u11.7.18-41.7.19-11.7.19-2 |
None known |
cjsonDebian:14 |
All versions, plus listed versions 1.7.18-3.11.7.18-41.7.19-11.7.19-2 |
None known |
cjsonRoot:Alpine:3.21 |
before 1.7.19-r00072 | 1.7.19-r000721.7.19-r00071 |
rootio-cjsonRoot:Alpine:3.21 |
before 1.7.19-r00072 | 1.7.19-r000721.7.19-r00071 |
cjsonRoot:Alpine:3.23 |
before 1.7.19-r10071 | 1.7.19-r100711.7.19-r100741.7.19-r100721.7.19-r10073 |
rootio-cjsonRoot:Alpine:3.23 |
before 1.7.19-r10071 | 1.7.19-r100711.7.19-r100741.7.19-r100721.7.19-r10073 |
iperf3Ubuntu:Pro:16.04:LTS |
All versions, plus listed versions 3.0.11-13.0.11-1ubuntu0.1~esm13.0.11-1ubuntu0.1~esm2 |
None known |
mapcacheUbuntu:16.04:LTS |
All versions, plus listed versions 1.4.0-31.4.0-4 |
None known |
Show 19 moreShow less
| Package | Affected | Fixed |
|---|---|---|
iperf3Ubuntu:Pro:18.04:LTS |
All versions, plus listed versions 3.1.3-13.1.3-1ubuntu0.1~esm1 |
None known |
mapcacheUbuntu:18.04:LTS |
All versions, plus listed versions 1.6.0-21.6.1-1 |
None known |
cjsonUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 1.7.10-1.11.7.10-1.1ubuntu0.1~esm1 |
None known |
iperf3Ubuntu:Pro:20.04:LTS |
All versions, plus listed versions 3.6-23.7-13.7-23.7-33.7-3ubuntu0.1~esm13.7-3ubuntu0.1~esm2 |
None known |
mapcacheUbuntu:20.04:LTS |
All versions, plus listed versions 1.8.0-11.8.0-1build21.10.0-1 |
None known |
mapcacheUbuntu:22.04:LTS |
All versions, plus listed versions 1.10.0-2build11.10.0-2build31.12.0-1 |
None known |
cjsonUbuntu:Pro:22.04:LTS |
All versions, plus listed versions 1.7.14-11.7.15-11.7.15-1ubuntu0.1~esm21.7.15-1ubuntu0.11.7.15-1ubuntu0.1+esm1 |
None known |
iperf3Ubuntu:Pro:22.04:LTS |
All versions, plus listed versions 3.9-13.9-1build13.9-1+deb11u1build0.22.04.13.9-1+deb11u1ubuntu0.1~esm13.9-1+deb11u1ubuntu0.1 |
None known |
mapcacheUbuntu:24.04:LTS |
All versions, plus listed versions 1.14.0-21.14.0-2build11.14.0-2build21.14.0-4build11.14.0-4build2 |
None known |
cjsonUbuntu:Pro:24.04:LTS |
All versions, plus listed versions 1.7.16-11.7.16-21.7.17-11.7.17-1ubuntu0.1~esm21.7.17-1ubuntu0.1~esm3 |
None known |
iperf3Ubuntu:Pro:24.04:LTS |
All versions, plus listed versions 3.14-13.15-13.16-13.16-1build13.16-1build23.16-1ubuntu0.1~esm1 |
None known |
cjsonUbuntu:26.10 |
All versions, plus listed versions 1.7.19-2 |
None known |
iperf3Ubuntu:26.10 |
All versions, plus listed versions 3.20-23.20-2.13.20-2.1build1 |
None known |
mapcacheUbuntu:26.10 |
All versions, plus listed versions 1.14.1-3build21.16.0-11.16.0-1build1 |
None known |
sail-ocamlUbuntu:26.10 |
All versions, plus listed versions 0.19.1+dfsg5-1build30.20.2+dfsg-1build1 |
None known |
cjsonUbuntu:26.04:LTS |
All versions, plus listed versions 1.7.18-3.11.7.18-41.7.19-11.7.19-2 |
None known |
iperf3Ubuntu:26.04:LTS |
All versions, plus listed versions 3.18-23.19.1-23.20-2 |
None known |
mapcacheUbuntu:26.04:LTS |
All versions, plus listed versions 1.14.1-31.14.1-3build11.14.1-3build2 |
None known |
sail-ocamlUbuntu:26.04:LTS |
All versions, plus listed versions 0.19.1+dfsg5-10.19.1+dfsg5-1build20.19.1+dfsg5-1build3 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-67216 is a high vulnerability (CVSS 8.2) in Cjson Project Cjson, published July 29, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.65%, the 51st percentile. Fixed in cjson 1.7.19-r00072.
References
joshua.hu/cjson-json-parser-cve-vulnerabilities
github.com/DaveGamble/cJSON/blob/v1.7.19/cJSON.c
vulncheck.com/advisories/cjson-cjson-compare-exponential-complexity-denial-of-service
nvd.nist.gov/vuln/detail/CVE-2026-67216
github.com/advisories/GHSA-ff2v-f99f-wm3f
github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67216.json
security-tracker.debian.org/tracker/CVE-2026-67216
ubuntu.com/security/CVE-2026-67216
cve.org/CVERecord?id=CVE-2026-67216