# CVE-2026-35611: sporkmonger Addressable ReDoS in URI templates

Source: https://junglewise.ai/threats/cve-2026-35611-sporkmonger-addressable-redos-in-uri-templates  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-07. Updated: 2026-05-13  
License: CC BY 4.0 with a link back

CVE-2026-35611 · Severity: high · CVSS 7.5 · Published 2026-04-07

Addressable is a Ruby library used for URI parsing and template matching. A vulnerability in its template matching component allows an attacker to cause a denial of service by providing a specially crafted URI. This can lead to excessive CPU consumption, potentially making the application unresponsive and impacting business operations.

Technologies: [addressable (RubyGems)](https://junglewise.ai/threats/technologies/addressable). Vendors: [RubyGems](https://junglewise.ai/threats/vendors/rubygems).

## Quick answers

**Is CVE-2026-35611 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-35611 being exploited in the wild.

**How severe is CVE-2026-35611?** High severity, with a CVSS score of 7.5, published 7 April 2026.

**Which products and versions are affected?** addressable (RubyGems) >= 2.3.0, < 2.9.0, ECOSYSTEM:introduced=2.3.0,fixed=2.9.0.

**Is there a fix for CVE-2026-35611?** Yes. addressable (RubyGems): upgrade to 2.9.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-35611 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-35611?** Check whether you run Addressable Project Addressable or 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.

## How to fix

- addressable (RubyGems): upgrade to 2.9.0 or later

  ```sh
  bundle update addressable
  ```


## Technical details

The URI template implementation in Addressable generates regular expressions vulnerable to catastrophic backtracking. Specifically, templates using the '*' (explode) modifier generate patterns with nested unbounded quantifiers (O(2^n) complexity), and templates using multiple variables with '+' or '#' operators generate patterns with O(n^k) complexity due to ambiguous backtracking across variables. An attacker can exploit this by providing a malicious URI to be matched against a vulnerable template, leading to uncontrolled resource consumption. The issue is fully remediated in version 2.9.0. MRI Ruby 3.2+ provides partial mitigation via Onigmo memoization, but JRuby and TruffleRuby remain fully vulnerable until the library is patched.

## Affected products

- sporkmonger addressable >= 2.3.0, < 2.9.0

## Identifiers

- CVE-2026-35611
- GHSA-h27x-rffw-24p4

## Timeline

- 2026-04-04: disclosed: Advisory published by maintainer
- 2026-04-07: advisory: NVD published CVE-2026-35611
- 2026-04-08: patched: Full remediation in version 2.9.0

## References

- [https://api.github.com/users/jamfish](https://api.github.com/users/jamfish)
- [https://github.com/jamfish](https://github.com/jamfish)
- [https://api.github.com/users/jamfish/gists%7B/gist_id%7D](https://api.github.com/users/jamfish/gists%7B/gist_id%7D)
- [https://api.github.com/users/jamfish/repos](https://api.github.com/users/jamfish/repos)
- [https://avatars.githubusercontent.com/u/3192230?v=4](https://avatars.githubusercontent.com/u/3192230?v=4)
- [https://api.github.com/users/jamfish/events%7B/privacy%7D](https://api.github.com/users/jamfish/events%7B/privacy%7D)

## Related threats

- [Addressable URI.normalize_path path traversal and bypass](https://junglewise.ai/threats/cve-2026-126354-addressable-uri-normalization-resolves-some-dotted-path-segments)
- [Addressable URI template ReDoS denial of service](https://junglewise.ai/threats/cve-2026-126352-addressable-is-an-alternative-implementation-to-the-uri)
- [Addressable URI path normalization denial of service](https://junglewise.ai/threats/cve-2026-126351-addressable-is-an-alternative-implementation-to-the-uri)
- [Addressable regular expression denial of service in URI template matching](https://junglewise.ai/threats/cve-2026-126350-addressable-is-an-alternative-implementation-to-the-uri)
- [Addressable display_uri can show misleading hosts containing bidi and invisible characters](https://junglewise.ai/threats/cve-2026-126349-addressable-is-an-alternative-implementation-to-the-uri)