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Vulnerability Details :

CVE-2026-33807

Summary
Assigner-openjs
Assigner Org ID-ce714d77-add3-4f53-aff5-83d477b104bb
Published At-15 Apr, 2026 | 09:52
Updated At-15 Apr, 2026 | 13:09
Rejected At-
Credits

@fastify/express vulnerable to middleware path doubling causing authentication bypass in child plugin scopes

@fastify/express v4.0.4 and earlier contains a path handling bug in the onRegister function that causes middleware paths to be doubled when inherited by child plugins. When a child plugin is registered with a prefix that matches a middleware path, the middleware path is prefixed a second time, causing it to never match incoming requests. This results in complete bypass of Express middleware security controls, including authentication, authorization, and rate limiting, for all routes defined within affected child plugin scopes. No special configuration or request crafting is required. Upgrade to @fastify/express v4.0.5 or later.

Vendors
-
Not available
Products
-
Metrics (CVSS)
VersionBase scoreBase severityVector
Weaknesses
Attack Patterns
Solution/Workaround
References
HyperlinkResource Type
EPSS History
Score
Latest Score
-
N/A
No data available for selected date range
Percentile
Latest Percentile
-
N/A
No data available for selected date range
Stakeholder-Specific Vulnerability Categorization (SSVC)
â–¼Common Vulnerabilities and Exposures (CVE)
cve.org
Assigner:openjs
Assigner Org ID:ce714d77-add3-4f53-aff5-83d477b104bb
Published At:15 Apr, 2026 | 09:52
Updated At:15 Apr, 2026 | 13:09
Rejected At:
â–¼CVE Numbering Authority (CNA)
@fastify/express vulnerable to middleware path doubling causing authentication bypass in child plugin scopes

@fastify/express v4.0.4 and earlier contains a path handling bug in the onRegister function that causes middleware paths to be doubled when inherited by child plugins. When a child plugin is registered with a prefix that matches a middleware path, the middleware path is prefixed a second time, causing it to never match incoming requests. This results in complete bypass of Express middleware security controls, including authentication, authorization, and rate limiting, for all routes defined within affected child plugin scopes. No special configuration or request crafting is required. Upgrade to @fastify/express v4.0.5 or later.

Affected Products
Vendor
fastify
Product
@fastify/express
Default Status
unaffected
Versions
Affected
  • From 0 before 4.0.5 (semver)
Unaffected
  • 4.0.5 (semver)
Problem Types
TypeCWE IDDescription
CWECWE-436CWE-436: Interpretation Conflict
Type: CWE
CWE ID: CWE-436
Description: CWE-436: Interpretation Conflict
Metrics
VersionBase scoreBase severityVector
3.19.1CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Version: 3.1
Base score: 9.1
Base severity: CRITICAL
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions

Configurations

Workarounds

Exploits

Credits

reporter
FredKSchott
remediation developer
mcollina
remediation reviewer
UlisesGascon
remediation reviewer
climba03003
Timeline
EventDate
Replaced By

Rejected Reason

References
HyperlinkResource
https://github.com/fastify/fastify-express/security/advisories/GHSA-hrwm-hgmj-7p9c
N/A
https://cna.openjsf.org/security-advisories.html
N/A
Hyperlink: https://github.com/fastify/fastify-express/security/advisories/GHSA-hrwm-hgmj-7p9c
Resource: N/A
Hyperlink: https://cna.openjsf.org/security-advisories.html
Resource: N/A
â–¼Authorized Data Publishers (ADP)
CISA ADP Vulnrichment
Affected Products
Metrics
VersionBase scoreBase severityVector
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions

Configurations

Workarounds

Exploits

Credits

Timeline
EventDate
Replaced By

Rejected Reason

References
HyperlinkResource
https://github.com/fastify/fastify-express/security/advisories/GHSA-hrwm-hgmj-7p9c
exploit
Hyperlink: https://github.com/fastify/fastify-express/security/advisories/GHSA-hrwm-hgmj-7p9c
Resource:
exploit
Information is not available yet
â–¼National Vulnerability Database (NVD)
nvd.nist.gov
Source:ce714d77-add3-4f53-aff5-83d477b104bb
Published At:15 Apr, 2026 | 10:16
Updated At:17 Apr, 2026 | 15:38

@fastify/express v4.0.4 and earlier contains a path handling bug in the onRegister function that causes middleware paths to be doubled when inherited by child plugins. When a child plugin is registered with a prefix that matches a middleware path, the middleware path is prefixed a second time, causing it to never match incoming requests. This results in complete bypass of Express middleware security controls, including authentication, authorization, and rate limiting, for all routes defined within affected child plugin scopes. No special configuration or request crafting is required. Upgrade to @fastify/express v4.0.5 or later.

CISA Catalog
Date AddedDue DateVulnerability NameRequired Action
N/A
Date Added: N/A
Due Date: N/A
Vulnerability Name: N/A
Required Action: N/A
Metrics
TypeVersionBase scoreBase severityVector
Secondary3.19.1CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Type: Secondary
Version: 3.1
Base score: 9.1
Base severity: CRITICAL
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CPE Matches

Weaknesses
CWE IDTypeSource
CWE-436Secondaryce714d77-add3-4f53-aff5-83d477b104bb
CWE ID: CWE-436
Type: Secondary
Source: ce714d77-add3-4f53-aff5-83d477b104bb
Evaluator Description

Evaluator Impact

Evaluator Solution

Vendor Statements

References
HyperlinkSourceResource
https://cna.openjsf.org/security-advisories.htmlce714d77-add3-4f53-aff5-83d477b104bb
N/A
https://github.com/fastify/fastify-express/security/advisories/GHSA-hrwm-hgmj-7p9cce714d77-add3-4f53-aff5-83d477b104bb
N/A
https://github.com/fastify/fastify-express/security/advisories/GHSA-hrwm-hgmj-7p9c134c704f-9b21-4f2e-91b3-4a467353bcc0
N/A
Hyperlink: https://cna.openjsf.org/security-advisories.html
Source: ce714d77-add3-4f53-aff5-83d477b104bb
Resource: N/A
Hyperlink: https://github.com/fastify/fastify-express/security/advisories/GHSA-hrwm-hgmj-7p9c
Source: ce714d77-add3-4f53-aff5-83d477b104bb
Resource: N/A
Hyperlink: https://github.com/fastify/fastify-express/security/advisories/GHSA-hrwm-hgmj-7p9c
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Resource: N/A

Change History

0
Information is not available yet

Similar CVEs

6Records found

CVE-2026-33808
Matching Score-6
Assigner-ce714d77-add3-4f53-aff5-83d477b104bb
ShareView Details
Matching Score-6
Assigner-ce714d77-add3-4f53-aff5-83d477b104bb
CVSS Score-9.1||CRITICAL
EPSS-0.17% / 37.80%
||
7 Day CHG-0.00%
Published-15 Apr, 2026 | 09:29
Updated-17 Apr, 2026 | 15:38
Rejected-Not Available
Known To Be Used In Ransomware Campaigns?-Not Available
KEV Added-Not Available
KEV Action Due Date-Not Available
@fastify/express vulnerable to middleware authentication bypass via URL normalization gaps (duplicate slashes and semicolons)

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Action-Not Available
Vendor-fastify
Product-@fastify/express
CWE ID-CWE-436
Interpretation Conflict
CVE-2026-25223
Matching Score-6
Assigner-GitHub, Inc.
ShareView Details
Matching Score-6
Assigner-GitHub, Inc.
CVSS Score-7.5||HIGH
EPSS-0.02% / 5.47%
||
7 Day CHG~0.00%
Published-03 Feb, 2026 | 21:21
Updated-10 Feb, 2026 | 20:05
Rejected-Not Available
Known To Be Used In Ransomware Campaigns?-Not Available
KEV Added-Not Available
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Action-Not Available
Vendor-fastifyfastify
Product-fastifyfastify
CWE ID-CWE-436
Interpretation Conflict
CVE-2026-33804
Matching Score-4
Assigner-ce714d77-add3-4f53-aff5-83d477b104bb
ShareView Details
Matching Score-4
Assigner-ce714d77-add3-4f53-aff5-83d477b104bb
CVSS Score-7.4||HIGH
EPSS-0.06% / 19.49%
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7 Day CHG+0.01%
Published-16 Apr, 2026 | 13:56
Updated-22 Apr, 2026 | 17:30
Rejected-Not Available
Known To Be Used In Ransomware Campaigns?-Not Available
KEV Added-Not Available
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Action-Not Available
Vendor-@fastify/middieOpenJS Foundation
Product-\@fastify\/middie@fastify/middie
CWE ID-CWE-436
Interpretation Conflict
CVE-2026-6270
Matching Score-4
Assigner-ce714d77-add3-4f53-aff5-83d477b104bb
ShareView Details
Matching Score-4
Assigner-ce714d77-add3-4f53-aff5-83d477b104bb
CVSS Score-9.1||CRITICAL
EPSS-0.06% / 17.79%
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7 Day CHG-0.00%
Published-16 Apr, 2026 | 13:44
Updated-22 Apr, 2026 | 17:31
Rejected-Not Available
Known To Be Used In Ransomware Campaigns?-Not Available
KEV Added-Not Available
KEV Action Due Date-Not Available
@fastify/middie vulnerable to middleware authentication bypass in child plugin scopes

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Action-Not Available
Vendor-@fastify/middieOpenJS Foundation
Product-\@fastify\/middie@fastify/middie
CWE ID-CWE-436
Interpretation Conflict
CVE-2026-41248
Matching Score-4
Assigner-GitHub, Inc.
ShareView Details
Matching Score-4
Assigner-GitHub, Inc.
CVSS Score-9.1||CRITICAL
EPSS-0.11% / 29.09%
||
7 Day CHG~0.00%
Published-24 Apr, 2026 | 21:04
Updated-29 Apr, 2026 | 20:56
Rejected-Not Available
Known To Be Used In Ransomware Campaigns?-Not Available
KEV Added-Not Available
KEV Action Due Date-Not Available
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Action-Not Available
Vendor-clerk
Product-nuxtnextjsastroshared
CWE ID-CWE-436
Interpretation Conflict
CWE ID-CWE-863
Incorrect Authorization
CVE-2024-38428
Matching Score-4
Assigner-MITRE Corporation
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Matching Score-4
Assigner-MITRE Corporation
CVSS Score-9.1||CRITICAL
EPSS-0.20% / 41.28%
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7 Day CHG~0.00%
Published-16 Jun, 2024 | 00:00
Updated-21 Apr, 2025 | 10:15
Rejected-Not Available
Known To Be Used In Ransomware Campaigns?-Not Available
KEV Added-Not Available
KEV Action Due Date-Not Available

url.c in GNU Wget through 1.24.5 mishandles semicolons in the userinfo subcomponent of a URI, and thus there may be insecure behavior in which data that was supposed to be in the userinfo subcomponent is misinterpreted to be part of the host subcomponent.

Action-Not Available
Vendor-n/aGNU
Product-wgetn/awget
CWE ID-CWE-436
Interpretation Conflict
Details not found