High severity7.5NVD Advisory· Published Dec 10, 2021· Updated Jun 17, 2026
CVE-2021-43803
CVE-2021-43803
Description
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.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
nextnpm | >= 12.0.0, < 12.0.5 | 12.0.5 |
nextnpm | >= 0.9.9, < 11.1.3 | 11.1.3 |
Affected products
3Patches
Vulnerability mechanics
References
7- github.com/vercel/next.js/commit/6d98b4fb4315dec1badecf0e9bdc212a4272b264nvdPatchThird Party AdvisoryWEB
- github.com/vercel/next.js/pull/32080nvdPatchThird Party AdvisoryWEB
- github.com/vercel/next.js/security/advisories/GHSA-25mp-g6fv-mqxxnvdPatchThird Party AdvisoryWEB
- github.com/advisories/GHSA-25mp-g6fv-mqxxghsaADVISORY
- github.com/vercel/next.js/releases/tag/v11.1.3nvdRelease NotesThird Party AdvisoryWEB
- github.com/vercel/next.js/releases/v12.0.5nvdRelease NotesThird Party AdvisoryWEB
- nvd.nist.gov/vuln/detail/CVE-2021-43803ghsaADVISORY
News mentions
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