CVE-2023-36617 URI gem has ReDoS vulnerability

Medium 5.3 Published 29 Jun 2023 Updated 4 Nov 2025

Attackers can cause denial of service by submitting specially crafted URLs that trigger excessive parsing time in the Ruby URI library.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2023-36617?

CVE-2023-36617 is a medium-severity denial of service vulnerability in n/a, published on 29 Jun 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A ReDoS issue was discovered in the URI component before 0.12.2 for Ruby. The URI parser mishandles invalid URLs that have specific characters. There is an increase in execution time for parsing strings to URI objects with rfc2396_parser.rb and rfc3986_parser.rb. NOTE: this issue exists becuse of an incomplete fix for CVE-2023-28755. Version 0.10.3 is also a fixed version.

Weakness: CWE-1333

Which versions are affected by CVE-2023-36617?

8 open source packages ship an affected version, including uri. It affects 1 product.

Package	Affected	Fixed in
`uri` RubyGems	All versions	`0.10.0.3`
`uri` RubyGems	All versions	`0.10.0.3`
`uri` RubyGems	From `0.10.1`	`0.10.3`
`uri` RubyGems	From `0.10.1`	`0.10.3`
`uri` RubyGems	From `0.11.0`	`0.11.2`
`uri` RubyGems	From `0.11.0`	`0.11.2`

2 more packages

`uri` RubyGems	From `0.12.0`	`0.12.2`
`uri` RubyGems	From `0.12.0`	`0.12.2`

Products include Ruby-Lang Uri.

How do I fix CVE-2023-36617?

Upgrade uri to a fixed version for your release line: 0.10.0.3, 0.10.3, 0.11.2 or 0.12.2.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2023-36617 being exploited?

There is no known exploitation of CVE-2023-36617 in the wild and no public exploit code.

Sources

Also known as AZL-27310, CLSA-2025-1755617966, DEBIAN-CVE-2023-36617, GHSA-hww2-5g85-429m, OESA-2023-1427, UBUNTU-CVE-2023-36617 and 1 more.