Bug 2456062 (CVE-2026-35611)

Summary: CVE-2026-35611 addressable: Addressable: Denial of Service via crafted URI templates
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akostadi, amasferr, crizzo, dmayorov, jlledo, pantinor, tsedmik
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Addressable. This vulnerability allows a remote attacker to cause a Denial of Service (DoS) by providing a maliciously crafted Uniform Resource Identifier (URI) to the URI template implementation. Specifically, certain URI templates using the explode modifier or multiple variables with the plus or hash operators generate regular expressions vulnerable to catastrophic backtracking, leading to uncontrolled resource consumption.
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Description OSIDB Bzimport 2026-04-07 17:01:39 UTC
Addressable is an alternative implementation to the URI implementation that is part of Ruby's standard library. From 2.3.0 to before 2.9.0, within the URI template implementation in Addressable, two classes of URI template generate regular expressions vulnerable to catastrophic backtracking. Templates using the * (explode) modifier with any expansion operator (e.g., {foo*}, {+var*}, {#var*}, {/var*}, {.var*}, {;var*}, {?var*}, {&var*}) generate patterns with nested unbounded quantifiers that are O(2^n) when matched against a maliciously crafted URI. Templates using multiple variables with the + or # operators (e.g., {+v1,v2,v3}) generate patterns with O(n^k) complexity due to the comma separator being within the matched character class, causing ambiguous backtracking across k variables. When matched against a maliciously crafted URI, this can result in catastrophic backtracking and uncontrolled resource consumption, leading to denial of service. This vulnerability is fixed in 2.9.0.