fast-uri vulnerable to host confusion via failed IDN canonicalization

Summary

CVECVE-2026-13676
StatePUBLISHED
Assigneropenjs
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-06-29 14:16:47 UTC
Updated2026-06-30 03:17:14 UTC
Descriptionfast-uri versions 2.3.1 through 3.1.2 and 4.0.0 fail to canonicalize Unicode (IDN) hostnames for HTTP-family URLs. The IDN conversion path calls a helper that does not exist on the global URL constructor, silently leaving the host in its original Unicode form while normalize() and equal() still return values that differ from a WHATWG-compatible URL parser. Applications that use fast-uri to enforce host-based policy (denylists, loopback filtering, redirect validation, outbound proxy routing) before passing the same URL to Node's URL or fetch can be bypassed when the two implementations resolve the same input to different hosts. Patches: upgrade to fast-uri 3.1.3 for the 3.x line or 4.0.1 for the 4.x line. Workarounds: enforce host policy using the same URL parser used for the actual request, or reject non-ASCII hosts before policy checks.

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from ADP

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

EPSS: 0.002780000 probability, percentile 0.195360000 (date 2026-06-30)

Problem Types: CWE-436 | CWE-551 | CWE-436 CWE-436: Interpretation Conflict | CWE-551 Incorrect Behavior Order: Authorization Before Parsing and Canonicalization


VersionSourceTypeScoreSeverityVector
3.1ADPCVSS7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
3.1ce714d77-add3-4f53-aff5-83d477b104bbSecondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
3.10b0ca135-0b70-47e7-9f44-1890c2a1c46cSecondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
3.1CNACVSS7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Fast-uri Fast-uri affected 4.0.0 4.0.1 semver Not specified
CNA Fast-uri Fast-uri unaffected 4.0.1 semver Not specified
CNA Fast-uri Fast-uri affected 2.3.1 3.1.3 semver Not specified
CNA Fast-uri Fast-uri unaffected 3.1.3 semver Not specified
ADP Red Hat Confidential Compute Attestation Not specified Not specified
ADP Red Hat Cryostat 4 Not specified Not specified
ADP Red Hat Migration Toolkit For Applications 8 Not specified Not specified
ADP Red Hat Migration Toolkit For Containers Not specified Not specified
ADP Red Hat Multicluster Engine For Kubernetes Not specified Not specified
ADP Red Hat Network Observability Operator Not specified Not specified
ADP Red Hat OpenShift Lightspeed Not specified Not specified
ADP Red Hat OpenShift Pipelines Not specified Not specified
ADP Red Hat OpenShift Serverless Not specified Not specified
ADP Red Hat Red Hat Advanced Cluster Management For Kubernetes 2 Not specified Not specified
ADP Red Hat Red Hat AMQ Broker 7 Not specified Not specified
ADP Red Hat Red Hat Ansible Automation Platform 2 Not specified Not specified
ADP Red Hat Red Hat Build Of Apache Camel - HawtIO 4 Not specified Not specified
ADP Red Hat Red Hat Build Of Apicurio Registry 3 Not specified Not specified
ADP Red Hat Red Hat Build Of Podman Desktop Not specified Not specified
ADP Red Hat Red Hat Connectivity Link 1 Not specified Not specified
ADP Red Hat Red Hat Data Grid 8 Not specified Not specified
ADP Red Hat Red Hat Developer Hub Not specified Not specified
ADP Red Hat Red Hat Discovery 2 Not specified Not specified
ADP Red Hat Red Hat Edge Manager 1 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 10 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 9 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux AI RHEL AI 3 Not specified Not specified
ADP Red Hat Red Hat OpenShift AI RHOAI Not specified Not specified
ADP Red Hat Red Hat OpenShift Container Platform 4 Not specified Not specified
ADP Red Hat Red Hat Openshift Data Foundation 4 Not specified Not specified
ADP Red Hat Red Hat OpenShift Dev Spaces Not specified Not specified
ADP Red Hat Red Hat OpenShift Virtualization 4 Not specified Not specified
ADP Red Hat Red Hat Quay 3 Not specified Not specified
ADP Red Hat Red Hat Satellite 6 Not specified Not specified
ADP Red Hat Self-service Automation Portal 2 Not specified Not specified

References

ReferenceSourceLinkTags
cna.openjsf.org/security-advisories.html ce714d77-add3-4f53-aff5-83d477b104bb cna.openjsf.org
access.redhat.com/security/cve/CVE-2026-13676 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
bugzilla.redhat.com/show_bug.cgi 0b0ca135-0b70-47e7-9f44-1890c2a1c46c bugzilla.redhat.com
security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-13676.json 0b0ca135-0b70-47e7-9f44-1890c2a1c46c security.access.redhat.com
github.com/fastify/fast-uri/security/advisories/GHSA-4c8g-83qw-93j6 ce714d77-add3-4f53-aff5-83d477b104bb github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: celinke97 (en)

CNA: UlisesGascon (en)

Additional Advisory Data

SourceTimeEvent
ADP2026-06-29T14:01:55.592ZReported to Red Hat.
ADP2026-06-29T13:22:44.674ZMade public.

Workarounds

ADP: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

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