Next.js vulnerable to cache poisoning in React Server Component responses

### Impact Applications using React Server Components can be vulnerable to cache poisoning when shared caches do not correctly partition response variants. Under affected conditions, an attacker can cause an RSC response to be served from the original URL and poison shared cache entries so later visitors receive component payloads instead of the expected HTML. ### Fix We now validate and interpret `RSC` request headers consistently across request classification and rendering, and we enforce the intended cache-busting behavior so RSC payloads are not unexpectedly served from the original URL. ### Workarounds If you cannot upgrade immediately, ensure your CDN or reverse proxy keys on the relevant RSC request headers and honors `Vary`, or disable shared caching for affected App Router and RSC responses.

Source published

11 May 2026 15:54:46 UTC

Source modified

10 Sep 2026 03:50:47 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:L

Publisher rating · MODERATE