Addressable display_uri can show misleading hosts with invalid Punycode A-labels

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-126348
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-11-12 22:19:19 UTC
Updated2026-11-12 22:19:19 UTC
DescriptionAddressable is an alternative implementation to the URI implementation that is part of Ruby's standard library. From 2.0.0 until 2.9.1, the pure-Ruby Addressable::IDNA.to_unicode implementation decodes invalid Punycode A-labels instead of returning them unchanged. Labels that decode to ASCII text or fail to convert back to the same A-label can therefore make Addressable::URI#display_uri show a trusted-looking host while host, normalized_host, and the connection target retain the attacker-controlled encoded host. A trusted-name comparison using Addressable::IDNA.to_unicode output can also treat two different hosts as the same without displaying the URI. The native libidn implementation, to_ascii, and normalized_host are unaffected. This issue is fixed in version 2.9.1.

Risk And Classification

Primary CVSS: v3.1 4.3 MEDIUM from [email protected]

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

Problem Types: CWE-20 | CWE-1007 | CWE-20 CWE-20: Improper Input Validation | CWE-1007 CWE-1007: Insufficient Visual Distinction of Homoglyphs Presented to User

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary4.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
3.1CNADECLARED4.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

CVSS v3.1 Breakdown

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

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Sporkmonger Addressable affected >= 2.0.0, < 2.9.1 Not specified

References

ReferenceSourceLinkTags
github.com/sporkmonger/addressable/releases/tag/addressable-2.9.1 [email protected] github.com
github.com/sporkmonger/addressable/security/advisories/GHSA-9crm-g4mf-wc5j [email protected] github.com
github.com/sporkmonger/addressable/commit/b8a59cc0e03f8704f1d7c8122fc8f7... [email protected] github.com
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