SSRF via misclassified middleware Location header
Published Aug 29, 2025 · Updated Sep 2, 2025
SSRF in Next.js Middleware before 14.2.32 and before 15.4.7 allows remote attackers to access internal services via crafted headers. The self-hosted router treats a Location header returned with a non-redirect status as a rewrite target, allowing forwarded user-controlled headers to steer an internal request. Exploitation requires custom middleware that passes incoming headers directly to NextResponse.next() without the request object; Vercel-hosted deployments are not exposed.
Summary
What happened
SSRF in Next.js Middleware before 14.2.32 and before 15.4.7 allows remote attackers to access internal services via crafted headers. The self-hosted router treats a Location header returned with a non-redirect status as a rewrite target, allowing forwarded user-controlled headers to steer an internal request. Exploitation requires custom middleware that passes incoming headers directly to NextResponse.next() without the request object; Vercel-hosted deployments are not exposed.
The record
- CVE
- CVE-2025-57822
- Published
- Aug 29, 2025
- Updated
- Sep 2, 2025
- Vendor
- Vercel
- Product
- Next.js
- Classifications
- CWE-918, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 29, 2025CVE publishedPublication date reported by the CVE source.
- Sep 2, 2025Record 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=< 14.2.32
- Affected versionversion=< 15.4.7
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
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
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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