Skip to main content

Boteraser | Website and Server Security Solutions

🛡️ CVE-2026-44572 — next

🟢 CVSS 3.7 — Low ✅ No Known Exploit CWE-349 NVD
3.7
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Next.js's Middleware / Proxy redirects can be cache-poisoned

Impact

Next.js uses the x-nextjs-data request header for internal data requests. On affected versions, an external client could send this header on a normal request to a path handled by middleware that returns a redirect.

When that happened, the middleware/proxy could treat the request as a data request and replace the standard Location redirect header with the internal x-nextjs-redirect header. Browsers do not follow x-nextjs-redirect, so the response became an unusable redirect for normal clients.

If the application was deployed behind a CDN or reverse proxy that caches 3xx responses without varying on this header, a single attacker request could poison the cached redirect response for the affected path. Subsequent visitors could then receive a cached redirect response without a Location header, causing a denial of service for that redirect path until the cache entry expired or was purged.

Affected scenarios

This affects applications that:

  • use middleware or proxy redirects
  • are deployed behind a caching CDN or reverse proxy
  • allow 3xx responses on those paths to be cached without differentiating internal data requests from normal requests

Fix

The fix stops trusting x-nextjs-data by itself for middleware redirect handling. A request is now treated as an internal data request only when it is validated as such by internal routing state, preserving legitimate data-request redirect behavior while preventing external header injection from changing normal redirect responses.

Workarounds

Before upgrading, users can reduce risk by:

  • configuring the CDN or reverse proxy to vary its cache key on x-nextjs-data for affected responses

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is high, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability low.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: High — the attacker first has to win a race, learn a secret or otherwise prepare the target.
  • Privileges required: None — an unauthenticated stranger can try it.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: None.
  • Integrity impact: None.
  • Availability impact: Low — limited, and the attacker does not choose what is affected.

Weakness class

CVE-2026-44572 is classified as CWE-349: Acceptance of Extraneous Untrusted Data With Trusted Data. The product, when processing trusted data, accepts any untrusted data that is also included with the trusted data, treating the untrusted data as if it were trusted.

Affected software

CVE-2026-44572 is recorded against 2 packages.

  • next
  • next.js (from 16.0.0 up to 16.2.5)

Timeline and source

Published on 11 May 2026 and last revised on 14 May 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

github.com (Web)
nvd.nist.gov (Advisory)
github.com (Package)
github.com (Web)
github.com (Web)

Other advisories for this package

next has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-349: Acceptance of Extraneous Untrusted Data With Trusted Data) in other software:

Details

Severity LOW
CVSS Score 3.7
CVSS Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
CWE CWE-349
Public Exploit ✅ No
Source NVD
Published 2026-05-11
Updated 2026-08-20
Modified 2026-05-14
Fix URL N/A

Affected Packages

Software From version Fixed in
next — —
next.js 16.0.0 16.2.5

Similar Threats

Free Vulnerability Check

Is your site affected by CVE-2026-44572?

BotEraser helps you identify potentially vulnerable plugins and themes by checking your installation against CVE-2026-44572 and other known CVE records.

Scan My Site Free →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

Browse related advisories

All advisoriesCVECVE 2026
✓