# CVE-2023-26819: Denial of service in cJSON

> Attackers can cause denial of service in applications using cJSON by submitting crafted JSON documents with large numeric values.

- **Severity:** Low 2.9 (`CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 Apr 2025
- **Updated:** 3 Nov 2025
- **Also known as:** AZL-60883, AZL-60889, DEBIAN-CVE-2023-26819, GHSA-whx8-2789-8w4w, OESA-2025-1965, OESA-2025-1992, OESA-2025-1993, OESA-2025-1994, OESA-2025-1995, UBUNTU-CVE-2023-26819

## What is CVE-2023-26819?

CVE-2023-26819 is a low-severity denial of service vulnerability in cJSON, published on 19 Apr 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

cJSON 1.7.15 might allow a denial of service via a crafted JSON document such as {"a": true, "b": [ null,9999999999999999999999999999999999999999999999912345678901234567]}.

Weakness: CWE-440 (Expected Behavior Violation)

## Which versions are affected by CVE-2023-26819?

It affects 1 product.


Products: Cjson Project Cjson.

## How do I fix CVE-2023-26819?

Upgrade to a fixed version.

## Is CVE-2023-26819 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-26819 exists.

## Other vulnerabilities in cJSON

- [CVE-2024-31755](https://insights.sbomify.com/CVE-2024-31755/): Null dereference in n/a (high 7.6)
- [CVE-2023-53154](https://insights.sbomify.com/CVE-2023-53154/): Memory corruption in cJSON (low 2.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-26819 and fix it if it is affected.

What it is: CVE-2023-26819 is a low-severity denial of service vulnerability in cJSON, published on 19 Apr 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-26819 exists.

Affected product: cJSON. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-26819/ (Markdown: https://insights.sbomify.com/CVE-2023-26819/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-26819
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-26819
- OSV: https://osv.dev/vulnerability/CVE-2023-26819

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-26819/
Summaries are generated and may contain mistakes; the official description above is the record.