CVE-2026-64645
In versions 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, a rewrites() or redirects() rule that builds its external destination hostname from request-controlled input can be pointed at an arbitrary hostname, regardless of the rule's hostname suffix.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.84%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Next.js is a React framework for building full-stack web applications. In versions 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, a rewrites() or redirects() rule that builds its external destination hostname from request-controlled input can be pointed at an arbitrary hostname, regardless of the rule's hostname suffix. For a rewrite, Next.js proxies the request to that arbitrary host and serves the response from the application's origin, leading to Server-Side Request forgery. A redirects() rule configured this way is vulnerable to an Open Redirect. This issue has been fixed in versions 15.5.21 and 16.2.11.
- CVSS 4.0
- 8.3 HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.84% probability · 56th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-601, CWE-918
- Affected
- vercel/next.js
- Source
- security-advisories@github.com
References
- https://github.com/vercel/next.js/commit/35f501357e9b0fe7c950b0d6aa8fcf5343f707e9Patch
- https://github.com/vercel/next.js/commit/d3033266c6dff23f7be71e19341fe3a8c6e2c599Patch
- https://github.com/vercel/next.js/releases/tag/v15.5.21Product, Release Notes
- https://github.com/vercel/next.js/releases/tag/v16.2.11Product, Release Notes
- https://github.com/vercel/next.js/security/advisories/GHSA-p9j2-gv94-2wf4Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.