CVE-2026-126351

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of service disruption.

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-11-10 21:12 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-11-12 22:19 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-11-12 22:19 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: not scored yet.
• Severity: 5.9 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-11-12 22:19 UTC

Last modified

2026-11-12 22:19 UTC

Weakness

CWE-407

Record status

Received

Attack profile CVSS 3.1 · 5.9

Attack vector

Network

Complexity

High

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-126351.md and follow it. Check whether this project is affected by CVE-2026-126351. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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