{"id":"CVE-2026-47138","state":"PUBLISHED","title":"Parse Server: Pre-authentication denial of service via client version header regex backtracking","description":"Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.77 and 9.9.1-alpha.1, an unauthenticated attacker who knows a publicly-known Parse Application ID can submit a single HTTP request whose client SDK version field contains adversarial input that triggers polynomial backtracking in a request-header parser. The parsing runs before session authentication and before rate limiting on every /parse/* request, so the request consumes seconds to minutes of synchronous CPU on a Node.js worker before any access control evaluates it. A small number of concurrent requests can saturate a worker; a single large request via the body-field variant can pin a worker for minutes. Production deployments running the default configuration are affected. This issue has been patched in versions 8.6.77 and 9.9.1-alpha.1.","publishedAt":"2026-06-12T18:22:02.751Z","updatedAt":"2026-06-12T18:56:14.419Z","severity":{"score":8.7,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["parse-community parse-server"],"affected":[{"vendor":"parse-community","product":"parse-server","versions":[{"version":"< 8.6.77","status":"affected"},{"version":">= 9.0.0, < 9.9.1-alpha.1","status":"affected"}]}],"references":["https://github.com/parse-community/parse-server/security/advisories/GHSA-38m6-82c8-4xfm","https://github.com/parse-community/parse-server/pull/10463","https://github.com/parse-community/parse-server/pull/10464"],"weaknesses":["CWE-1333"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/47xxx/CVE-2026-47138.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-47138","state":"PUBLISHED","datePublished":"2026-06-12T18:22:02.751Z","dateUpdated":"2026-06-12T18:56:14.419Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-05-18T19:50:18.696Z"},"containers":{"cna":{"title":"Parse Server: Pre-authentication denial of service via client version header regex backtracking","descriptions":[{"lang":"en","value":"Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.77 and 9.9.1-alpha.1, an unauthenticated attacker who knows a publicly-known Parse Application ID can submit a single HTTP request whose client SDK version field contains adversarial input that triggers polynomial backtracking in a request-header parser. The parsing runs before session authentication and before rate limiting on every /parse/* request, so the request consumes seconds to minutes of synchronous CPU on a Node.js worker before any access control evaluates it. A small number of concurrent requests can saturate a worker; a single large request via the body-field variant can pin a worker for minutes. Production deployments running the default configuration are affected. This issue has been patched in versions 8.6.77 and 9.9.1-alpha.1."}],"affected":[{"vendor":"parse-community","product":"parse-server","versions":[{"version":"< 8.6.77","status":"affected"},{"version":">= 9.0.0, < 9.9.1-alpha.1","status":"affected"}]}],"references":[{"url":"https://github.com/parse-community/parse-server/security/advisories/GHSA-38m6-82c8-4xfm","name":"https://github.com/parse-community/parse-server/security/advisories/GHSA-38m6-82c8-4xfm","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/parse-community/parse-server/pull/10463","name":"https://github.com/parse-community/parse-server/pull/10463","tags":["x_refsource_MISC"]},{"url":"https://github.com/parse-community/parse-server/pull/10464","name":"https://github.com/parse-community/parse-server/pull/10464","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.7,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-1333","lang":"en","description":"CWE-1333: Inefficient Regular Expression Complexity","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-06-12T18:22:02.751Z"},"source":{"advisory":"GHSA-38m6-82c8-4xfm","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-12T18:56:09.032234Z","id":"CVE-2026-47138","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-12T18:56:14.419Z"}}]}}}