{"uid":"cap__mQ7gy06m_mgwZeVKcEtt","slug":"saylor-innovations-guide-library-regex-catastrophic-backtracking-redos-bd462ab4","name":"Saylor Innovations Guide Library: Regex Catastrophic Backtracking & ReDoS","description":"Fix catastrophic regex backtracking and ReDoS - nested quantifier patterns, rewrites with atomic groups, input limits and linear-time engines like RE2","url":"https://saylorinnovations.com/api/kb/regex-catastrophic-backtracking-redos?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string","const":"json"},"example":{"type":"object","required":["id","t","c","body"],"properties":{"c":{"type":"string","description":"Category of the guide"},"t":{"type":"string","description":"Title of the guide"},"id":{"type":"string","description":"Identifier of the record"},"body":{"type":"string","description":"Main body text"},"price":{"type":["number","null"],"description":"Price"},"license":{"type":"string","description":"License identifier"}}}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_Xcv65IlaGYyQsriLd0-Gd","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns a reference guide on fixing catastrophic regex backtracking and ReDoS vulnerabilities, covering nested quantifier patterns, atomic group rewrites, input limits, and linear-time engines like RE2","exampleAgentPrompt":"Can you pull up the guide on fixing catastrophic regex backtracking and ReDoS? I need to understand how to rewrite nested quantifier patterns using atomic groups and when to switch to a linear-time engine like RE2.","exampleUseCases":[{"title":"Securing a web app from ReDoS","prompt":"My API endpoint uses a user-supplied regex and I'm worried about denial-of-service attacks — can you get me the guide on ReDoS and catastrophic backtracking so I can understand what patterns to avoid and how to mitigate the risk?"},{"title":"Rewriting a slow nested-quantifier regex","prompt":"I have a regex with nested quantifiers that hangs for certain inputs and I can't figure out why — fetch me the guide on catastrophic backtracking so I can learn how to rewrite it using atomic groups."},{"title":"Choosing a safe regex engine","prompt":"I'm evaluating whether to switch our regex engine to RE2 for linear-time guarantees — can you retrieve the Saylor Innovations guide on ReDoS so I can compare approaches including input limits and engine alternatives?"}],"resultDescription":"Returns a JSON object with a guide record including: a unique identifier (id), the guide title (t), the category (c), and the full body text (body) explaining catastrophic regex backtracking and ReDoS — covering nested quantifier patterns, atomic group rewrites, input length limits, and linear-time engines such as RE2. Also includes a license identifier and optional price.","failureModes":["Endpoint unavailable or returns non-200 status if the service is down","Payment not completed or x402 payment header missing/invalid — request rejected","Guide content may not reflect the very latest regex engine features or CVEs","Response body may be truncated if the guide text is very long"],"whenToPreferThis":"Choose this endpoint when you need a focused, immediately usable reference guide on ReDoS and catastrophic regex backtracking — particularly when you want concise coverage of nested quantifier hazards, atomic group rewrites, input-length mitigations, and linear-time engine options like RE2. Prefer it over general web search when you want a curated, structured document rather than raw search results, and over an LLM's built-in knowledge when you want a canonical, versioned reference you can cite.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-30T07:21:14.258Z","isFirstParty":false,"canonicalSlug":"saylor-innovations-guide-library-regex-catastrophic-backtracking-redos-bd462ab4"}