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CVE-2025-29927· NVD / CVE Program· CNA GitHub_M

Authorization Bypass in Next.js Middleware

Next.js is a React framework for building full-stack web applications. Starting in version 1.11.4 and prior to versions 12.3.5, 13.5.9, 14.2.25, and 15.2.3, it is possible to bypass authorization checks within a Next.js application, if the authorization check occurs in middleware. If patching to a safe version is infeasible, it is recommend that you prevent external user requests which contain the x-middleware-subrequest header from reaching your Next.js application. This vulnerability is fixed in 12.3.5, 13.5.9, 14.2.25, and 15.2.3.

CriticalCVSS 9.1 · v3.1—Weaponized Fix available
Published
Mar 21, 2025
Updated
Jun 17, 2026
EPSS
99.2% · 100th percentile
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Report tools

JSON

Action score

66

This week

Don’t wait for the next maintenance window.

CVSS
36 / 40 · 9.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
30 / 30 · 99.2%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
9.1
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Affected systems

VendorProduct
vercelnext.js

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • vercel next.js11.1.4 and later · before 12.3.5
  • vercel next.js13.0.0 and later · before 13.5.9
  • vercel next.js14.0.0 and later · before 14.2.25
  • vercel next.js15.0.0 and later · before 15.2.3

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • vercel next.js

    • >= 11.1.4, < 12.3.5, >= 14.0.0, < 14.2.25, >= 15.0.0, < 15.2.3, >= 13.0.0, < 13.5.9affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
npmnextfrom 12.0.0 · before 12.3.512.3.5
npmnextfrom 13.0.0 · before 13.5.913.5.9
npmnextfrom 14.0.0 · before 14.2.2514.2.25
npmnextfrom 15.0.0 · before 15.2.315.2.3

Same product

vercel: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-46982Cache Poisoning in next.js
    48Plan
  • CVE-2021-43803Unexpected server crash in Next.js
    43Plan
  • CVE-2025-55183An information leak vulnerability exists in specific configurations of React Server Components versions 19.0.0, 19.0.1 19.1.0, 19.1.1, 19.1.
    40Plan
  • CVE-2026-75604Next.js: Unauthenticated Remote Code Execution on windows-hosted servers
    37Monitor
  • CVE-2026-44578Next.js: Server-side request forgery in applications using WebSocket upgrades
    35Monitor
  • CVE-2026-64649Next.js: Server-Side Request Forgery in Server Actions on Custom Servers
    33Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
vercel next.js12.3.5 · descriptionVendor (CNA)
npm:next12.3.5Package registry (OSV)
npm:next13.5.9Package registry (OSV)
npm:next14.2.25Package registry (OSV)
npm:next15.2.3Package registry (OSV)

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Metasploit module ×1
  • Exploit-DB entry ×1
  • Nuclei detection template ×2
  • Proof-of-concept repository on GitHub ×50

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Nuclei detection templateNuclei template CVE-2025-29927-HEADLESS —
Exploit-DB entrywebapps2025-04-05
Metasploit moduleauxiliary/scanner/http/nextjs_middleware_auth_bypassNext.js Middleware Authorization Bypass Scannerauxiliary2025-03-21
Nuclei detection templateNuclei template CVE-2025-29927 —
Proof-of-concept repository on GitHubstars:02025-03-22
Proof-of-concept repository on GitHubstars:42025-03-22
Proof-of-concept repository on GitHubstars:192025-03-23
Proof-of-concept repository on GitHubstars:152025-03-23
Proof-of-concept repository on GitHubstars:142025-03-23
Proof-of-concept repository on GitHubstars:1032025-03-23
Proof-of-concept repository on GitHubstars:02025-03-23
Proof-of-concept repository on GitHubstars:42025-03-23

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Metasploitsame day
  2. Published
  3. First PoC+1 d
  4. TodaySep 29, 2026+557 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-64642493 days apartNext.js: Middleware / Proxy bypass in App Router applications using Turbopack and single locale
    33Monitor
  • CVE-2024-5147994 days apartAuthorization bypass in Next.js
    31Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
None

Weakness class (CWE)

CWE-285 · Improper Authorization

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Noroxi analysis

No Noroxi analysis for this record yet

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Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records