Red Hat CVE-2026-29057
MEDIUM
GHSA-ggv3-7p47-pfv8
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V4 - API and Web Service HTTP request consistency
|
| Impact | CVSS 6.5. EPSS 0.1%. Vendor patch available. |
| Exploit ScenarioDerived | An attacker could exploit this vulnerability in the affected application to compromise the security of affected deployments, potentially impacting confidentiality, integrity, or availability. |
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Alert meAnalysisAIv1 – Mar 17, 2026
CVE-2026-29057 is a security vulnerability (CVSS 6.5) that allows request smuggling. Remediation should follow standard vulnerability management procedures. Vendor patch is available.
Earlier versions of this analysis (1)
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 ba
RemediationAI
Apply the vendor-supplied patch immediately.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in npm
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
Vulnerability type not specified by vendor.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Primary rating from GitHub Advisory.
CVSS VectorGitHub Advisory
Lifecycle Timeline
2DescriptionGitHub Advisory
Summary
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.
Impact
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.
Patches
The vulnerability originated in an upstream library vendored by Next.js. It is fixed 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.
Workarounds
If upgrade is not immediately possible:
- Block chunked
DELETE/OPTIONSrequests on rewritten routes at your edge/proxy. - Enforce authentication/authorization on backend routes per our security guidance.
Blast Radius
ecosystem impact- 10 npm packages depend on next (9 direct, 1 indirect)
Ecosystem-wide dependent count for version 16.0.0-beta.0.
Executive ViewAI
CVE-2026-29057 presents notable security risk rated CVSS 6.5. Exploitation could compromise the security of affected deployments. A patch is available and should be applied during regular vulnerability management.
Apply vendor patch. If patching is delayed: restrict network access and enable monitoring.
Threat Intelligence Overview
NVD
CVE.org
EPSS
VulDB
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
HTTP request smuggling exploits inconsistencies in how front-end and back-end servers parse HTTP message boundaries.
Exploit-DB