Cache poisoning via inconsistent RSC header interpretation
Published May 13, 2026 · Updated May 13, 2026
Cache poisoning in Next.js 14.2.0 through 15.5.15 and 16.0.0 through 16.2.4 allows remote attackers to corrupt shared cache entries. Request classification and rendering interpret the RSC header inconsistently and fail to enforce cache busting, allowing an RSC payload to occupy the original URL's shared cache entry. Exploitation requires React Server Components behind a shared cache that does not partition relevant response variants; later visitors receive component payloads instead of HTML.
Summary
What happened
Cache poisoning in Next.js 14.2.0 through 15.5.15 and 16.0.0 through 16.2.4 allows remote attackers to corrupt shared cache entries. Request classification and rendering interpret the RSC header inconsistently and fail to enforce cache busting, allowing an RSC payload to occupy the original URL's shared cache entry. Exploitation requires React Server Components behind a shared cache that does not partition relevant response variants; later visitors receive component payloads instead of HTML.
The record
- CVE
- CVE-2026-44576
- Published
- May 13, 2026
- Updated
- May 13, 2026
- Vendor
- Vercel
- Product
- Next.js
- Classifications
- CWE-436, T1491.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 13, 2026CVE publishedPublication date reported by the CVE source.
- May 13, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 14.2.0, < 15.5.16
- Affected versionversion=>= 16.0.0, < 16.2.5
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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