CVE-2026-44572Network attack vector

Redirect-path denial of service via trusted external header

Published May 13, 2026 · Updated May 13, 2026

Cache poisoning in Vercel Next.js 12.2.0 through 15.5.15 and 16.0.0 through 16.2.4 allows remote attackers to disrupt redirect paths. Middleware redirect handling accepts the external x-nextjs-data header as proof of an internal data request and replaces Location with x-nextjs-redirect. Exploitation requires a middleware or proxy redirect behind a cache that stores 3xx responses without distinguishing internal data requests.

CVSS severity3.7
Low
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cache poisoning in Vercel Next.js 12.2.0 through 15.5.15 and 16.0.0 through 16.2.4 allows remote attackers to disrupt redirect paths. Middleware redirect handling accepts the external x-nextjs-data header as proof of an internal data request and replaces Location with x-nextjs-redirect. Exploitation requires a middleware or proxy redirect behind a cache that stores 3xx responses without distinguishing internal data requests.

The record

CVE
CVE-2026-44572
Published
May 13, 2026
Updated
May 13, 2026
Vendor
Vercel
Product
Next.js
Classifications
CWE-349, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 13, 2026CVE publishedPublication date reported by the CVE source.
  2. 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.

  1. Affected versionversion=>= 12.2.0, < 15.5.16
  2. Affected versionversion=>= 16.0.0, < 16.2.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Vercel · Next.jsversion=>= 12.2.0, < 15.5.16; version=>= 16.0.0, < 16.2.5

Published CVSS scores

3.7GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
5.9NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-349Acceptance of Extraneous Untrusted Data With Trusted Data
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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