CVE-2026-126348
Addressable display_uri can show misleading hosts with invalid Punycode A-labels
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.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| addressable sporkmonger |
>= 2.0.0, < 2.9.1 (affected) | CNA: GitHub_M |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 4.3 medium |
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N | CNA: GitHub_M |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/sporkmonger/addressable/security/advisories/GHSA-9crm-g4mf-wc5jCNA: GitHub_M · x_refsource_CONFIRM
- https://github.com/sporkmonger/addressable/commit/b8a59cc0e03f8704f1d7c8122fc8f7ef8548362dCNA: GitHub_M · x_refsource_MISC
- https://github.com/sporkmonger/addressable/releases/tag/addressable-2.9.1CNA: GitHub_M · x_refsource_MISC
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