# CVE-2026-21717: Denial of service in node

> Attackers can cause denial of service in Node.js applications by triggering predictable hash collisions in V8's string hashing mechanism via crafted JSON input.

- **Severity:** Medium 5.9 (`CVSS:3.0/AV:N/AC:H/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:** 30 Mar 2026
- **Updated:** 10 May 2026
- **Also known as:** ALPINE-CVE-2026-21717, AZL-81245, BELL-CVE-2026-21717, BIT-node-2026-21717, BIT-node-min-2026-21717, CLEANSTART-2026-UC30604, DEBIAN-CVE-2026-21717, GHSA-326m-34v3-gv5p, MINI-4438-x946-whp3, MINI-4j2p-x6p7-jhpp, MINI-63qw-42q3-h82j, MINI-gpw8-8m9c-96hv, MINI-h4q5-969g-r925, MINI-q944-6q2x-g3hx, MINI-qpqh-r3m7-wmgc, UBUNTU-CVE-2026-21717

## What is CVE-2026-21717?

CVE-2026-21717 is a medium-severity denial of service vulnerability in Nodejs Node.js, published on 30 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw in V8's string hashing mechanism causes integer-like strings to be hashed to their numeric value, making hash collisions trivially predictable. By crafting a request that causes many such collisions in V8's internal string table, an attacker can significantly degrade performance of the Node.js process.

The most common trigger is any endpoint that calls `JSON.parse()` on attacker-controlled input, as JSON parsing automatically internalizes short strings into the affected hash table.

This vulnerability affects **20.x, 22.x, 24.x, and 25.x**.

Weakness: CWE-328 (Use of Weak Hash)

## Which versions are affected by CVE-2026-21717?

2 open source packages ship an affected version, including node and node-min. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `node` | Bitnami | All versions | 20.20.2, 22.22.2, 24.14.1, 25.8.2 |
| `node-min` | Bitnami | All versions | 20.20.2, 22.22.2, 24.14.1, 25.8.2 |

Products: Nodejs Node.js.

## How do I fix CVE-2026-21717?

Upgrade node to a fixed version for your release line: 20.20.2, 22.22.2, 24.14.1 or 25.8.2.

## Is CVE-2026-21717 being exploited?

There is no known exploitation of CVE-2026-21717 in the wild and no public exploit code.

Public exploit code:

- https://github.com/open-flaw/CVE-2026-21717 (github_poc): https://github.com/open-flaw/CVE-2026-21717

## Other vulnerabilities in Nodejs Node.js

- [CVE-2023-32002](https://insights.sbomify.com/CVE-2023-32002/): Security feature bypass in Node (critical 9.8)
- [CVE-2016-6303](https://insights.sbomify.com/CVE-2016-6303/): Integer overflow in n/a (critical 9.8)
- [CVE-2017-15896](https://insights.sbomify.com/CVE-2017-15896/): Security feature bypass in Node.js (critical 9.1)
- [CVE-2018-7160](https://insights.sbomify.com/CVE-2018-7160/): Server-side request forgery in Node.js (high 8.8)
- [CVE-2018-12120](https://insights.sbomify.com/CVE-2018-12120/): Misconfiguration in Node.js (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-21717 and fix it if it is affected.

What it is: CVE-2026-21717 is a medium-severity denial of service vulnerability in Nodejs Node.js, published on 30 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-21717 in the wild and no public exploit code.

Affected packages and fixed versions:
- node (Bitnami): affected all versions; fixed in 20.20.2, 22.22.2, 24.14.1, 25.8.2
- node-min (Bitnami): affected all versions; fixed in 20.20.2, 22.22.2, 24.14.1, 25.8.2

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-2026-21717/ (Markdown: https://insights.sbomify.com/CVE-2026-21717/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-21717
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-21717
- OSV: https://osv.dev/vulnerability/CVE-2026-21717

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-21717/
Summaries are generated and may contain mistakes; the official description above is the record.