CVE-2026-128117
What it is
SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. Prior to versions 2.70.4 and 3.1.1, the reroute hook could rewrite an invalid percent-encoded pathname into a valid route and reach a comparison that decoded the original malformed pathname outside the guarded decoding operation. The resulting unhandled URIError could crash an adapter-node server and deny service to other requests. This issue is fixed in 2.70.4 and 3.1.1.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of service disruption.
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- ReservedThe CVE id was reserved by its CNA
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: not scored yet.
- Severity: 5.9 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Weakness
- CWE-248
- Record status
- Deferred
Attack profile CVSS 3.1 · 5.9
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-128117.md and follow it. Check whether this project is affected by CVE-2026-128117. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/sveltejs/kit/commit/0a2e58cbccdd46cac20aa5af4e2edf17e0da11dd
- https://github.com/sveltejs/kit/commit/7993d5ebab017cb1be898a0b1c57371c5da06557
- https://github.com/sveltejs/kit/pull/17620
- https://github.com/sveltejs/kit/releases/tag/@sveltejs/[email protected]
- https://github.com/sveltejs/kit/releases/tag/@sveltejs/[email protected]
- https://github.com/sveltejs/kit/security/advisories/GHSA-mw6w-2fmv-pvw3
References
- https://github.com/sveltejs/kit/commit/0a2e58cbccdd46cac20aa5af4e2edf17e0da11dd
- https://github.com/sveltejs/kit/commit/7993d5ebab017cb1be898a0b1c57371c5da06557
- https://github.com/sveltejs/kit/pull/17620
- https://github.com/sveltejs/kit/releases/tag/@sveltejs/[email protected]
- https://github.com/sveltejs/kit/releases/tag/@sveltejs/[email protected]
- https://github.com/sveltejs/kit/security/advisories/GHSA-mw6w-2fmv-pvw3