{"id":"CVE-2026-53724","state":"PUBLISHED","title":"Parse Server: Stored XSS via trailing-dot filename bypassing file upload extension blocklist","description":"Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.79 and 9.9.1-alpha.4, the default file upload extension blocklist can be bypassed by appending a trailing dot to a filename whose extension would otherwise be blocked (e.g. poc.svg.). The trailing dot causes the extension parser to extract an empty string, which short-circuits the blocklist check, and the attacker-controlled Content-Type is forwarded to the storage adapter unchanged. Storage adapters that persist and serve the provided Content-Type (such as S3 or GCS) then serve the file with an active type such as image/svg+xml, enabling stored XSS when a victim opens the file URL. The default GridFS adapter is not affected because it sets X-Content-Type-Options: nosniff on responses. This issue has been patched in versions 8.6.79 and 9.9.1-alpha.4.","publishedAt":"2026-06-12T18:34:38.237Z","updatedAt":"2026-06-12T20:01:13.569Z","severity":{"score":2.1,"label":"Low","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["parse-community parse-server"],"affected":[{"vendor":"parse-community","product":"parse-server","versions":[{"version":"< 8.6.79","status":"affected"},{"version":">= 9.0.0, < 9.9.1-alpha.4","status":"affected"}]}],"references":["https://github.com/parse-community/parse-server/security/advisories/GHSA-7wqv-xjf3-x35v","https://github.com/parse-community/parse-server/pull/10489","https://github.com/parse-community/parse-server/pull/10490"],"weaknesses":["CWE-434","CWE-79"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53724.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53724","state":"PUBLISHED","datePublished":"2026-06-12T18:34:38.237Z","dateUpdated":"2026-06-12T20:01:13.569Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-10T16:43:31.242Z"},"containers":{"cna":{"title":"Parse Server: Stored XSS via trailing-dot filename bypassing file upload extension blocklist","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 8.6.79 and 9.9.1-alpha.4, the default file upload extension blocklist can be bypassed by appending a trailing dot to a filename whose extension would otherwise be blocked (e.g. poc.svg.). The trailing dot causes the extension parser to extract an empty string, which short-circuits the blocklist check, and the attacker-controlled Content-Type is forwarded to the storage adapter unchanged. Storage adapters that persist and serve the provided Content-Type (such as S3 or GCS) then serve the file with an active type such as image/svg+xml, enabling stored XSS when a victim opens the file URL. The default GridFS adapter is not affected because it sets X-Content-Type-Options: nosniff on responses. This issue has been patched in versions 8.6.79 and 9.9.1-alpha.4."}],"affected":[{"vendor":"parse-community","product":"parse-server","versions":[{"version":"< 8.6.79","status":"affected"},{"version":">= 9.0.0, < 9.9.1-alpha.4","status":"affected"}]}],"references":[{"url":"https://github.com/parse-community/parse-server/security/advisories/GHSA-7wqv-xjf3-x35v","name":"https://github.com/parse-community/parse-server/security/advisories/GHSA-7wqv-xjf3-x35v","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/parse-community/parse-server/pull/10489","name":"https://github.com/parse-community/parse-server/pull/10489","tags":["x_refsource_MISC"]},{"url":"https://github.com/parse-community/parse-server/pull/10490","name":"https://github.com/parse-community/parse-server/pull/10490","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"PASSIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","subAvailabilityImpact":"NONE","baseScore":2.1,"baseSeverity":"LOW","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-434","lang":"en","description":"CWE-434: Unrestricted Upload of File with Dangerous Type","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-06-12T18:34:38.237Z"},"source":{"advisory":"GHSA-7wqv-xjf3-x35v","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-12T19:03:39.906463Z","id":"CVE-2026-53724","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-12T20:01:13.569Z"}}]}}}