# CVE-2026-128122: SvelteKit: Prerendered redirect paths can inject arbitrary rules into the `_redirects` file generated by `@sveltejs/adapter-cloudflare`

Status: published. Published: 2026-11-13. Updated: 2026-11-13.

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. From version 4.7.0 until versions 7.2.10 and 8.0.2, @sveltejs/adapter-cloudflare allowed an attacker-influenced link crawled during prerendering to place whitespace, control characters, wildcards, or placeholders into a prerendered redirect path. The adapter wrote those paths into the Cloudflare _redirects output without output-context validation, allowing a path to create unintended routing rules that could redirect or expose requests beyond the intended prerendered route. This issue is fixed in 7.2.10 and 8.0.2.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- sveltejs / kit: >= 4.7.0, < 7.2.10 (affected); >= 8.0.0-next.0, < 8.0.2 (affected). Source: CNA: GitHub_M

## Severity and prioritization

- CVSS 3.1: 5.9 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N; source: CNA: GitHub_M

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-79, CWE-93, CWE-116

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/sveltejs/kit/security/advisories/GHSA-5wg4-q3ww-283h (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/sveltejs/kit/pull/17620 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/sveltejs/kit/commit/0a2e58cbccdd46cac20aa5af4e2edf17e0da11dd (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/sveltejs/kit/commit/679e0d84ea9951bb4f1e458a599066b5a451b08a (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/sveltejs/kit/releases/tag/@sveltejs/adapter-cloudflare@7.2.10 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/sveltejs/kit/releases/tag/@sveltejs/adapter-cloudflare@8.0.2 (CNA: GitHub_M; x_refsource_MISC)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-128122; retrieved 2026-11-13; source updated 2026-11-13

Revision: 49113b8f921c5a78adc37c6a4b20898264e8942659cdaa74e04eaa3151283fb3

Canonical: https://y2.dev/cve/CVE-2026-128122

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