Next.jsApplication · Vercel

CVE-2026-44576

MEDIUM · 5.4 CVSS v3.1 Published 2026-05-13
Fix available
A fix is available. Upgrade to 15.5.16 / 16.2.5 or later.
See remediation →
63/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Next.js is a React framework for building full-stack web applications. From 14.2.0 to before 15.5.16 and 16.2.5, 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. This vulnerability is fixed in 15.5.16 and 16.2.5.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Next.js versions 14.2.0 through 15.5.15 and before 16.2.5 contain a cache poisoning vulnerability in React Server Components. When shared caches fail to correctly partition response variants, an attacker can poison cache entries so subsequent visitors receive RSC component payloads instead of the expected HTML from the original URL.

MitigationUpgrade Next.js to version 15.5.16 or 16.2.5 or later. Review application caching configurations and consider implementing additional cache validation to ensure proper response partitioning.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Next.jsApplication
Affected:>= 14.2.0, < 15.5.16>= 16.0.0, < 16.2.5

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Scope
Changed
Confidentiality
None
Integrity
Low
Availability
Low

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Determine installed Next.js version
    Run `npm list next` in the project directory or check the package.json dependencies field
    Affected if Version is 14.2.0 through 15.5.15, or 16.0.0 through 16.2.4
  2. Confirm React Server Components are in use
    Check if the application uses the App Router (app directory) or explicitly imports from 'react' server components, which is the default behavior in Next.js 14.2+
    Affected if App Router is used, as RSC is enabled by default in affected versions
  3. Verify caching is enabled
    Inspect next.config.js or next.config.mjs for caching configurations such as `experimental` or `experimental` settings, or check for use of `unstable_cache` / `cache` functions in the codebase
    Affected if Any form of RSC caching or shared cache mechanisms are configured

User is affected if Next.js version falls within 14.2.0 to 15.5.15 or 16.0.0 to 16.2.4, and the application uses React Server Components with caching enabled.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 15.5.16 / 16.2.5 or later
Fixed in 15.5.1616.2.5
Interim mitigation

Upgrade Next.js to version 15.5.16 or 16.2.5 or later. Review application caching configurations and consider implementing additional cache validation to ensure proper response partitioning.

Recommended fix High confidence

Next.js 15.5.16 (for v15 line) or 16.2.5 (for v16 line)

  1. Check current Next.js version in package.json or package-lock.json
  2. If using Next.js 15.x, run: npm install [email protected] or yarn add [email protected]
  3. If using Next.js 16.x, run: npm install [email protected] or yarn add [email protected]
  4. Clear any shared cache layers (e.g., CDN, reverse proxy) to remove poisoned entries
  5. Verify the upgrade by running your test suite, particularly any RSC-related tests
  6. Deploy and monitor for any issues
Caveat Review Next.js changelog between your current version and target version for any breaking changes; upgrading minor/patch versions typically has low risk but test thoroughly

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Next.js Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing8.0 h
  • Review / QA4.0 h
18.0 hours of engineering $3,040
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-44576 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data