Denial of Service Vulnerability in next.js
Impact
Vulnerable code could allow a bad actor to trigger a denial of service attack for anyone running a Next.js app at version >= 12.0.0, and using i18n functionality.
- Affected: All of the following must be true to be affected by this CVE
- Next.js versions above v12.0.0
- Using next start or a custom server
- Using the built-in i18n support
- Not affected:
- Deployments on Vercel (vercel.com) are not affected along with similar environments where invalid requests are filtered before reaching Next.js.
Patches
A patch has been released, next@12.0.9, that mitigates this issue. We recommend all affected users upgrade as soon as possible.
Workarounds
We recommend upgrading whether you can reproduce or not although you can ensure /${locale}/_next/ is blocked from reaching the Next.js instance until you upgrade.
For more information
If you have any questions or comments about this advisory:
- Open an issue in next
- Email us at security@vercel.com
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | next | >= 12.0.0, < 12.0.9 | 12.0.9 |
References
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H- Weakness (CWE)
CWE-20, CWE-400- Platform
- npm
- Package
next- Disclosed
- 28.01.2022
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-wr66-vrwm-5g5x - CC BY 4.0
Vulnerability history: next
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 73
- First → latest
- 12.2017 10.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 5
- High 27
- Medium 32
- Low 9
Disclosures per year
- 2017: 1
- 2018: 2
- 2019: 0
- 2020: 3
- 2021: 3
- 2022: 3
- 2023: 1
- 2024: 6
- 2025: 14
- 2026: 40
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Denial of Service Vulnerability in next.js this entry
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