NIST deprecates RSA-2048 from 2030. Find every one of them before attackers do.
🛡️
Not in CISA KEV
LOW severity

CVE-2026-126349 — Sporkmonger

LOWFix: sporkmonger/addressable@60455d3

CVE-2026-126349 is a low-severity (CVSS 3.1) CWE-176 vulnerability. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.

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…

Published
Updated
Affected
—
Patched
See advisory
Exploits
None indexed
Exploitation data as of Nov 12, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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, 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.

Detection & mitigation playbook

Vulnerability

  1. Detect

    Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

  2. Remediation status

    The records we use list no fixed release for CVE-2026-126349. Check the upstream advisory for a patched version, and apply the exposure-reduction steps below in the meantime.

  3. Mitigate without a patch

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

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
O3 Security · Impact-Aware SCA

Is CVE-2026-126349 in your dependencies?

Find it across your dependency tree, including transitive dependencies.

Scan my dependencies How O3 SCA works
CVE-2026-126349: Sporkmonger (Low 3.1)