CVE-2026-128121
SvelteKit: Prerendered paths are interpreted as regular expressions in Vercel route config generated by @sveltejs/adapter-vercel and @sveltejs/adapter-static
SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. Prior to @sveltejs/adapter-vercel 6.3.5 and 7.0.2 and @sveltejs/adapter-static 3.0.11 and 4.0.1, an attacker-influenced link crawled during prerendering could be emitted into the generated Vercel routing configuration without escaping regular-expression metacharacters. The configuration could consequently interpret the path as regular-expression syntax, match unintended application paths, and expose content or behavior outside the intended path. This issue is fixed in @sveltejs/adapter-vercel 6.3.5 and 7.0.2 and @sveltejs/adapter-static 3.0.11 and 4.0.1.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| kit sveltejs |
< 2.70.4 (affected) >= 3.0.0-next.0, < 3.1.1 (affected) |
CNA: GitHub_M |
| adapter-vercel @sveltejs |
< 6.3.5 (affected) >= 7.0.0-next.0, < 7.0.2 (affected) |
CNA: GitHub_M |
| adapter-static @sveltejs |
< 3.0.11 (affected) >= 4.0.0-next.0, < 4.0.1 (affected) |
CNA: GitHub_M |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 5.9 medium |
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N | CNA: GitHub_M |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/sveltejs/kit/security/advisories/GHSA-jf9x-2fg2-hx4wCNA: GitHub_M · x_refsource_CONFIRM
- https://github.com/sveltejs/kit/pull/17620CNA: GitHub_M · x_refsource_MISC
- https://github.com/sveltejs/kit/commit/0a2e58cbccdd46cac20aa5af4e2edf17e0da11ddCNA: GitHub_M · x_refsource_MISC
- https://github.com/sveltejs/kit/commit/2ed61a6aa3ac230b89e3528654c587847d1525a0CNA: GitHub_M · x_refsource_MISC
- https://github.com/sveltejs/kit/releases/tag/@sveltejs/[email protected]CNA: GitHub_M · x_refsource_MISC
- https://github.com/sveltejs/kit/releases/tag/@sveltejs/[email protected]CNA: GitHub_M · x_refsource_MISC
- https://github.com/sveltejs/kit/releases/tag/@sveltejs/[email protected]CNA: GitHub_M · x_refsource_MISC
- https://github.com/sveltejs/kit/releases/tag/@sveltejs/[email protected]CNA: GitHub_M · x_refsource_MISC
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