CVE-2026-87933: DaveGamble cJSON · Use After Free
Affects DaveGamble cJSONSource CVE Database V5
Public exploit available · CVSS 6.9 Medium.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 44% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- Proof of concept is public or traded
- Automatable
- Attackers can reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-09-10.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:PExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 10 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CISA SSVC: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by VulDB
, 8 hours before disclosure
CVE published
on cve.org
, t = 0
CISA SSVC assessment
proof of concept public
, 18 hours after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| DaveGamblecJSON | Affected
| Fixed in– |
CPE configurations (1)
cpe:2.3:a:davegamble:cjson:*:*:*:*:*:*:*:*
AI-suggested
A fix for this vulnerability is not yet officially released; a pull request with a patch is awaiting acceptance. Users should monitor the official DaveGamble cJSON repository for the merged fix and update to the patched version once available. Until then, consider applying the patch from the pull request manually if feasible. No vendor advisory indicates alternative mitigations or workarounds at this time.
Description
CVE-2026-87933 is a use-after-free vulnerability in the cJSON library by DaveGamble, affecting versions 1.7.0 through 1.7.19. The flaw exists in the cJSONUtils_MergePatch function within the cJSON_Utils.c file. This vulnerability can be exploited remotely without authentication. Public exploit code is available, but a fix is pending acceptance of a pull request.
References
- vuldb.com/vuln/401815 (opens in a new tab)
- vuldb.com/vuln/401815/cti (opens in a new tab)
- vuldb.com/cve/CVE-2026-87933 (opens in a new tab)
- vuldb.com/submit/911136 (opens in a new tab)
- github.com/DaveGamble/cJSON/issues/1060 (opens in a new tab)
- github.com/DaveGamble/cJSON/pull/1065 (opens in a new tab)
- github.com/DaveGamble/cJSON/ (opens in a new tab)