Quick answers
- Is CVE-2026-126352 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-126352 being exploited in the wild.
- How severe is CVE-2026-126352?
- Medium severity, with a CVSS score of 5.9, published 12 November 2026.
- Which products and versions are affected?
- Addressable 2.3.0 through 2.9.0; addressable (RubyGems) >= 2.3.0, < 2.9.1.
- Is there a fix for CVE-2026-126352?
- Yes: fixed in 2.9.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-126352 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-126352?
- Check whether you run 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
- Fixed in: 2.9.1
Technical details
The vulnerability exists in URI template matching logic (Template#match and Template#extract methods) where certain template patterns with multiple variables or adjacent expressions generate ambiguous regular expressions. On Ruby runtimes without regex match memoization (MRI before 3.2, JRuby, TruffleRuby), attacker-controlled URIs can cause polynomial or exponential regex backtracking, resulting in denial of service. URI parsing and Template#expand are unaffected.
Affected products
- Addressable Addressable 2.3.0 through 2.9.0
Identifiers
- CVE-2026-126352
- GHSA-9f42-57jx-vpp3
Timeline
- 2026-11-12: disclosed