Addressable 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.
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Thu, 12 Nov 2026 22:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Addressable 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. | |
| Title | Addressable display_uri can show misleading hosts with invalid Punycode A-labels | |
| Weaknesses | CWE-1007 CWE-20 |
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cvssV3_1
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-11-12T21:57:55.237Z
Reserved: 2026-11-10T21:12:01.227Z
Link: CVE-2026-126348
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Status : Received
Published: 2026-11-12T22:19:19.930
Modified: 2026-11-12T22:19:19.930
Link: CVE-2026-126348
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OpenCVE Enrichment
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