# CVE-2026-32141: flatted: Unbounded recursion DoS in parse() revive phase

> An attacker can crash the Node.js process by sending crafted JSON with deep nesting to the flatted parser, causing a stack overflow.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Mar 2026
- **Updated:** 4 Sep 2026
- **Also known as:** AZL-80312, CLEANSTART-2026-BE82466, CLEANSTART-2026-CH50712, CLEANSTART-2026-KQ19093, CLSA-2026-1792232973, DEBIAN-CVE-2026-32141, GHSA-25h7-pfq9-p65f, MINI-4p6w-8m7m-rvhm, MINI-4r64-g3px-289v, MINI-cg4r-f3g5-vq37, MINI-m6mg-j3cf-3qx5, MINI-qgqx-v5pj-x24v, MINI-xrr4-w4x6-54fw, ROOT-APP-NPM-CVE-2026-32141, UBUNTU-CVE-2026-32141

## What is CVE-2026-32141?

CVE-2026-32141 is a high-severity denial of service vulnerability in WebReflection flatted, published on 12 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

flatted is a circular JSON parser. Prior to 3.4.0, flatted's parse() function uses a recursive revive() phase to resolve circular references in deserialized JSON. When given a crafted payload with deeply nested or self-referential $ indices, the recursion depth is unbounded, causing a stack overflow that crashes the Node.js process. This vulnerability is fixed in 3.4.0.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-674 (Uncontrolled Recursion)

## Which versions are affected by CVE-2026-32141?

2 open source packages ship an affected version, including flatted. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `flatted` | npm | All versions | 3.4.0 |
| `flatted` | npm | All versions | 3.4.0 |

Products: Webreflection Flatted.

## How do I fix CVE-2026-32141?

Upgrade flatted to 3.4.0 or later.

## Is CVE-2026-32141 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-32141 exists.

## Other vulnerabilities in WebReflection flatted

- [CVE-2026-33228](https://insights.sbomify.com/CVE-2026-33228/): flatted: Prototype Pollution via parse() (high 8.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-32141 and fix it if it is affected.

What it is: CVE-2026-32141 is a high-severity denial of service vulnerability in WebReflection flatted, published on 12 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-32141 exists.

Affected packages and fixed versions:
- flatted (npm): affected all versions; fixed in 3.4.0
- flatted (npm): affected all versions; fixed in 3.4.0

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-2026-32141/ (Markdown: https://insights.sbomify.com/CVE-2026-32141/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-32141
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-32141
- OSV: https://osv.dev/vulnerability/CVE-2026-32141

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-32141/
Summaries are generated and may contain mistakes; the official description above is the record.