CVE-2026-126349: Addressable display_uri can show misleading hosts containing bidi and invisible characters
CVE-2026-126349 · Severity: low · CVSS 3.1 · Published 2026-11-12
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, Addressable::IDNA.to_unicode can decode Punycode labels that contain bidirectional controls, zero-width characters, control characters, or other default-ignorable format characters. Addressable::URI#display_uri can consequently show a reordered or visually indistinguishable hostname even though host, normalized_host, and network connections use the original encoded hostname. The pure-Ruby backend accepts the full prohibited set, while the native libidn backend is affected from 2.5.2 for characters added after Unicode 3.2. This issue is fixed in version 2.9.1.
No. Junglewise Threat Intelligence has no report of CVE-2026-126349 being exploited in the wild.
How severe is CVE-2026-126349?
Low severity, with a CVSS score of 3.1, published 12 November 2026.
Which products and versions are affected?
addressable (RubyGems) >= 2.0.0, < 2.9.1.
Is there a fix for CVE-2026-126349?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
Am I affected by CVE-2026-126349?
Check whether you run addressable (RubyGems) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.