Unexpected server crash in Next.js.
Next.js is a React framework. In versions of Next.js prior to 12.0.5 or 11.1.3, invalid or malformed URLs could lead to a server crash. In order to be affected by this issue, the deployment must use Next.js versions above 11.1.0 and below 12.0.5, Node.js above 15.0.0, and next start or a custom server. Deployments on Vercel are not affected, along with similar environments where invalid requests are filtered before reaching Next.js. Versions 12.0.5 and 11.1.3 contain patches for this issue. Note that prior version 0.9.9 package next hosted a different utility (0.4.1 being the latest version of that codebase), and this advisory does not apply to those versions.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | next | >= 12.0.0, < 12.0.5, >= 0.9.9, < 11.1.3 | 12.0.5, 11.1.3 |
References
- https://github.com/vercel/next.js/security/advisories/GHSA-25mp-g6fv-mqxx
- https://nvd.nist.gov/vuln/detail/CVE-2021-43803
- https://github.com/vercel/next.js/pull/32080
- https://github.com/vercel/next.js/commit/6d98b4fb4315dec1badecf0e9bdc212a4272b264
- https://github.com/vercel/next.js
- https://github.com/vercel/next.js/releases/tag/v11.1.3
- https://github.com/vercel/next.js/releases/v12.0.5
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Weakness (CWE)
CWE-20- Platform
- npm
- Package
next- Disclosed
- 07.12.2021
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-25mp-g6fv-mqxx - 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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Unexpected server crash in Next.js. this entry
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