{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55520","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-06-16T22:44:22.284Z","datePublished":"2026-08-28T18:42:38.334Z","dateUpdated":"2026-08-31T18:54:01.091Z"},"containers":{"cna":{"title":"Protego: Exponential backtracking ReDoS in robots.txt URL wildcard matching","problemTypes":[{"descriptions":[{"cweId":"CWE-400","lang":"en","description":"CWE-400: Uncontrolled Resource Consumption","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-1333","lang":"en","description":"CWE-1333: Inefficient Regular Expression Complexity","type":"CWE"}]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":7.1,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"}}],"references":[{"name":"https://github.com/scrapy/protego/security/advisories/GHSA-wjmf-p669-5m5p","tags":["x_refsource_CONFIRM"],"url":"https://github.com/scrapy/protego/security/advisories/GHSA-wjmf-p669-5m5p"},{"name":"https://github.com/scrapy/protego/commit/785940181659bf440ba82f1da148fade5087e858","tags":["x_refsource_MISC"],"url":"https://github.com/scrapy/protego/commit/785940181659bf440ba82f1da148fade5087e858"},{"name":"https://github.com/scrapy/protego/releases/tag/0.6.2","tags":["x_refsource_MISC"],"url":"https://github.com/scrapy/protego/releases/tag/0.6.2"}],"affected":[{"vendor":"scrapy","product":"protego","versions":[{"version":"< 0.6.2","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-08-28T18:42:38.334Z"},"descriptions":[{"lang":"en","value":"Protego is a pure-Python robots.txt parser with support for modern conventions. Prior to 0.6.2, protego._urlpattern._URLPattern._prepare_pattern_for_regex translates every asterisk in an Allow or Disallow directive into a lazy regular-expression wildcard, so a directive containing many asterisks creates exponential backtracking. After protego.Protego.parse processes a crafted robots.txt file, protego.Protego.can_fetch can spend an attacker-controlled period matching a near-miss URL and deny service to the crawler. The vulnerable path is src/protego/_urlpattern.py in the _URLPattern match logic. This issue is fixed in version 0.6.2."}],"source":{"advisory":"GHSA-wjmf-p669-5m5p","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-31T15:42:18.385319Z","id":"CVE-2026-55520","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-08-31T18:54:01.091Z"}}]}}