Next.js is a React framework for building full-stack web applications. Starting in version 9.5.0 and prior to versions 15.5.13 and 16.1.7, when Next.js rewrites proxy traffic to an external backend, a crafted `DELETE`/`OPTIONS` request using `Transfer-Encoding: chunked` could trigger request boundary disagreement between the proxy and backend. This could allow request smuggling through rewritten routes. An attacker could smuggle a second request to unintended backend routes (for example, internal/admin endpoints), bypassing assumptions that only the configured rewrite destination/path is reachable. This does not impact applications hosted on providers that handle rewrites at the CDN level, such as Vercel. The vulnerability originated in an upstream library vendored by Next.js. It is fixed in Next.js 15.5.13 and 16.1.7 by updating that dependency’s behavior so `content-length: 0` is added only when both `content-length` and `transfer-encoding` are absent, and `transfer-encoding` is no longer removed in that code path. If upgrading is not immediately possible, block chunked `DELETE`/`OPTIONS` requests on rewritten routes at the edge/proxy, and/or enforce authentication/authorization on backend routes.

The version of Next.js installed on the remote host is 9.5.0 prior to 15.5.14 or 16.0.0 prior to 16.1.7. It is, therefore, affected by multiple vulnerabilities:

- An HTTP request smuggling vulnerability in rewrites. This issue is fixed in versions 15.5.13 and 16.1.7. (CVE-2026-29057)

- A denial of service vulnerability due to unbounded next/image disk cache growth, which can exhaust storage. This issue only affects versions 10.0.0 and later. (CVE-2026-27980)

- A Cross-Site Request Forgery vulnerability where a null origin can bypass Server Actions CSRF checks. This issue only affects versions 16.0.1 and later. (CVE-2026-27978)

- An origin validation bypass where a null origin can bypass allowedDevOrigins protections for internal development endpoints. This issue only affects versions 16.0.1 and later. (CVE-2026-27977)

- A denial of service vulnerability due to unbounded postponed resume buffering. This issue only affects versions 16.1.0 and later. (CVE-2026-27979)

Note that the scanner has not attempted to exploit these issues but has instead relied only on application's self-reported version number.

The Next.js Framework on the remote host is affected by an HTTP request smuggling vulnerability:

  - A vulnerability exists in Next.js proxy rewrites where a crafted DELETE/OPTIONS request using     Transfer-Encoding: chunked could trigger request boundary disagreement between the proxy and backend. An     attacker could smuggle a second request to unintended backend routes such as internal or admin endpoints,     bypassing assumptions that only the configured rewrite destination path is reachable. This vulnerability     does not affect Vercel-hosted applications. (CVE-2026-29057)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Next.js is a React framework for building full-stack web applications. Starting in version 9.5.0 and prior     to versions 15.5.13 and 16.1.7, when Next.js rewrites proxy traffic to an external backend, a crafted     `DELETE`/`OPTIONS` request using `Transfer-Encoding: chunked` could trigger request boundary disagreement     between the proxy and backend. This could allow request smuggling through rewritten routes. An attacker     could smuggle a second request to unintended backend routes (for example, internal/admin endpoints),     bypassing assumptions that only the configured rewrite destination/path is reachable. This does not impact     applications hosted on providers that handle rewrites at the CDN level, such as Vercel. The vulnerability     originated in an upstream library vendored by Next.js. It is fixed in Next.js 15.5.13 and 16.1.7 by     updating that dependency's behavior so `content-length: 0` is added only when both `content-length` and     `transfer-encoding` are absent, and `transfer-encoding` is no longer removed in that code path. If     upgrading is not immediately possible, block chunked `DELETE`/`OPTIONS` requests on rewritten routes at     the edge/proxy, and/or enforce authentication/authorization on backend routes. (CVE-2026-29057)

Note that Nessus relies on the presence of the package as reported by the vendor.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - Next.js is a React framework for building full-stack web applications. Starting in version 9.5.0 and prior
    to versions 15.5.13 and 16.1.7, when Next.js rewrites proxy traffic to an external backend, a crafted
    `DELETE`/`OPTIONS` request using `Transfer-Encoding: chunked` could trigger request boundary disagreement
    between the proxy and backend. This could allow request smuggling through rewritten routes. An attacker
    could smuggle a second request to unintended backend routes (for example, internal/admin endpoints),
    bypassing assumptions that only the configured rewrite destination/path is reachable. This does not impact
    applications hosted on providers that handle rewrites at the CDN level, such as Vercel. The vulnerability
    originated in an upstream library vendored by Next.js. It is fixed in Next.js 15.5.13 and 16.1.7 by
    updating that dependency’s behavior so `content-length: 0` is added only when both `content-length` and
    `transfer-encoding` are absent, and `transfer-encoding` is no longer removed in that code path. If
    upgrading is not immediately possible, block chunked `DELETE`/`OPTIONS` requests on rewritten routes at
    the edge/proxy, and/or enforce authentication/authorization on backend routes. (CVE-2026-29057)

ID	Name	Product	Family	Type	Severity
115761	Next.js 16.0.x < 16.1.7 Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	Version Based	medium
115760	Next.js 9.5.0 < 15.5.14 Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	Version Based	medium
303201	Next.js Framework 9.5.x < 15.5.3 / 16.x < 16.1.7 HTTP Request Smuggling (GHSA-ggv3-7p47-pfv8)	Nessus	Misc.	Local	medium
302928	Linux Distros Unpatched Vulnerability : CVE-2026-29057	Nessus	Misc.	Local	medium
438894	SCA: security update for next (GHSA-ggv3-7p47-pfv8)	Tenable Cloud Security	SCA Checks	Local	medium
438894	SCA: security update for next (GHSA-ggv3-7p47-pfv8)	Tenable Self-Hosted Container Security	SCA Checks	Local	medium

Detections

Analytics

CVE-2026-29057

medium

Tenable Plugins

medium

medium

medium

medium

medium

medium