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CVE intelligence

CVE-2026-126351

Vulnerability intelligence

Published Nov 12, 2026Sources checked Nov 13, 2026
5.9MEDIUMCVSS out of 10
What this means

Review the available evidence

CVE-2026-126351 and is rated Medium severity with a CVSS score of 5.9. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Nov 14, 2026

Release Notes

CISA KEVNot listedBased on the latest collected catalog
EPSSUnavailableNo current score collected
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview

What is CVE-2026-126351?

Addressable is an alternative implementation to the URI implementation that is part of Ruby's standard library. Prior to 2.9.1, Addressable::URI.normalize_path repeatedly scans and rewrites paths while removing only one nested dot segment per pass, producing quadratic work.

URI#normalize, URI#normalized_path, URI#join, URI#==, and URI#=== inherit the behavior, so processing a sufficiently long attacker-controlled URI can consume a worker thread and cause denial of service on every Ruby implementation. URI.parse alone and code that never normalizes, compares, or joins untrusted URIs are unaffected.

This issue is fixed in version 2.9.1.

Source: NVD