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

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). 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
    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

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