PT-2026-20872 · Npm · @Sveltejs/Adapter-Vercel

Published 2026-02-19 · Updated 2026-02-19

OSV

CVSS v4.0

5.3

Medium

Base vector

AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Versions of @sveltejs/adapter-vercel prior to 6.3.2 are vulnerable to cache poisoning. An internal query parameter intended for Incremental Static Regeneration (ISR) is accessible on all routes, allowing an attacker to cause sensitive user-specific responses to be cached and served to other users.

Successful exploitation requires a victim to visit an attacker-controlled link while authenticated.

Existing deployments are protected by Vercel's WAF, but users should upgrade as soon as possible.

Fix

Origin Validation Error

Weakness Enumeration

CWE-346

Related Identifiers

GHSA-9PQ4-5HCF-288C

Affected Products

@Sveltejs/Adapter-Vercel

References · 4

• https://osv.dev/vulnerability/GHSA-9pq4-5hcf-288c · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-27118 · Security Note
• https://github.com/sveltejs/kit · Note
• https://github.com/sveltejs/kit/security/advisories/GHSA-9pq4-5hcf-288c · Note