CVE-2026-67215: cJSON through 1.7.19 is vulnerable to uncontrolled recursion leading to stack exhaustion when an untrusted RFC

This week

HIGH 7.5REMOTEUPGRADE

CVE-2026-67215 is a high-severity flaw (CVSS 7.5) affecting cjson. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

cJSON through 1.7.19 is vulnerable to uncontrolled recursion leading to stack exhaustion when an untrusted RFC 6902 JSON Patch is applied via cJSONUtils_ApplyPatches() or cJSONUtils_ApplyPatchesCaseSensitive(). A patch containing add and copy operations grafts duplicated subtrees to amplify document depth beyond the parser's nesting limit: cJSON_Delete() recurses with no depth bound, and the cJSON_Duplicate() guard CJSON_CIRCULAR_LIMIT is set to

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 47%)
CISA exploited list	No
Weakness	CWE-674
Published	2026-07-29
Last modified	2026-10-23

Publisher (CNA): VulnCheck · Vendor: davegamble

Am I affected?

Timeline

2026-07-29 14:16 UTCPublished CVE record published
2026-10-23 23:10 UTCUpdated Record last modified

davegamble cjson UPGRADE

Affected: <= 1.7.19

Fixed in: newer than 1.7.19

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy cjson || rpm -q cjson || cjson --version

2. UPGRADE to newer than 1.7.19 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade cjson

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade cjson

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Fedora 46 · python-fontconfig · FIXED · 0.6.3-1.fc46 · FEDORA-2026-f92ca8b01f · source

sudo dnf upgrade --advisory=FEDORA-2026-f92ca8b01f

Fedora ELN · valgrind · FIXED · 3.28.0-1.eln159 · FEDORA-2026-c593ef1d15 · source

sudo dnf upgrade --advisory=FEDORA-2026-c593ef1d15

Debian 12 · cjson · NO FIX YET

Debian 13 · cjson · NO FIX YET

RHEL 8 · rpm-ostree · NOT AFFECTED

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: joshua.hu/cjson-json-parser-cve-vulnerabilities

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Related CVEs

CVE-2026-67216 MEDIUM 5.9 UPGRADE cJSON through 1.7.19 contains an inefficient algorithmic complexity flaw in cJSON_Compare()
CVE-2026-67217 MEDIUM 5.3 UPGRADE cJSON through 1.7.19 applies RFC 6902 JSON Patch operations non-atomically in apply_patch() in cJSON_Utils.c

References

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