Reversible One-Way Hash in Next.js - #VU130274
Published: May 6, 2026
Vulnerability identifier: #VU130274
CSH Severity: Low
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: N/A
CWE-ID: CWE-328
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Next.js
Next.js
Software vendor:
vercel
vercel
Description
The vulnerability allows a remote attacker to poison shared cache entries and cause users to receive the wrong response variant for a given URL.
The vulnerability exists due to use of a weak hash in the React Server Component cache-busting mechanism when generating the _rsc cache-busting value for shared caches with insufficient response partitioning. A remote attacker can trigger collisions in crafted requests to poison shared cache entries and cause users to receive the wrong response variant for a given URL.
Only deployments that rely on shared caches with insufficient response partitioning are vulnerable.
Remediation
Install security update from vendor's website.