{"id":"CVE-2026-55696","state":"PUBLISHED","title":"PrivateBin: Stored Cross-Side-Scripting (XSS) vulnerability in attachment download link via dangerous MIME types with required user-interaction","description":"PrivateBin is an online pastebin where the server has zero knowledge of pasted data. Prior to 2.0.5, AttachmentViewer.setAttachment in js/privatebin.js uses getAttachmentMimeType to accept attacker-controlled MIME types and uses getBlobUrl to create a same-origin blob before setting attachmentLink's href for the Download attachment link. The SVG-only sanitization branch updates only the preview blob, so text/html, image/svg, application/xhtml+xml, and text/xml attachments can remain active in the download blob. On an instance with fileupload = true and a weakened, stripped, or absent Content Security Policy, an anonymous attacker can create such an attachment, and a victim who opens the link in a new tab causes inline JavaScript to execute in the PrivateBin origin. The script can read origin-scoped local storage and issue same-origin requests, including requests to applications co-hosted on the same domain. This issue is fixed in version 2.0.5.","publishedAt":"2026-08-28T20:20:53.934Z","updatedAt":"2026-08-31T18:53:53.698Z","severity":{"score":4.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["PrivateBin PrivateBin"],"affected":[{"vendor":"PrivateBin","product":"PrivateBin","versions":[{"version":"< 2.0.5","status":"affected"}]}],"references":["https://github.com/PrivateBin/PrivateBin/security/advisories/GHSA-f2xf-7x3g-4272","https://github.com/PrivateBin/PrivateBin/commit/7f1f40853efe0eb12db9cc4a30ea8524ac00f423","https://github.com/PrivateBin/PrivateBin/releases/tag/2.0.5"],"weaknesses":["CWE-79","CWE-80"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55696.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55696","state":"PUBLISHED","datePublished":"2026-08-28T20:20:53.934Z","dateUpdated":"2026-08-31T18:53:53.698Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-17T00:13:10.650Z"},"containers":{"cna":{"title":"PrivateBin: Stored Cross-Side-Scripting (XSS) vulnerability in attachment download link via dangerous MIME types with required user-interaction","descriptions":[{"lang":"en","value":"PrivateBin is an online pastebin where the server has zero knowledge of pasted data. Prior to 2.0.5, AttachmentViewer.setAttachment in js/privatebin.js uses getAttachmentMimeType to accept attacker-controlled MIME types and uses getBlobUrl to create a same-origin blob before setting attachmentLink's href for the Download attachment link. The SVG-only sanitization branch updates only the preview blob, so text/html, image/svg, application/xhtml+xml, and text/xml attachments can remain active in the download blob. On an instance with fileupload = true and a weakened, stripped, or absent Content Security Policy, an anonymous attacker can create such an attachment, and a victim who opens the link in a new tab causes inline JavaScript to execute in the PrivateBin origin. The script can read origin-scoped local storage and issue same-origin requests, including requests to applications co-hosted on the same domain. This issue is fixed in version 2.0.5."}],"affected":[{"vendor":"PrivateBin","product":"PrivateBin","versions":[{"version":"< 2.0.5","status":"affected"}]}],"references":[{"url":"https://github.com/PrivateBin/PrivateBin/security/advisories/GHSA-f2xf-7x3g-4272","name":"https://github.com/PrivateBin/PrivateBin/security/advisories/GHSA-f2xf-7x3g-4272","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/PrivateBin/PrivateBin/commit/7f1f40853efe0eb12db9cc4a30ea8524ac00f423","name":"https://github.com/PrivateBin/PrivateBin/commit/7f1f40853efe0eb12db9cc4a30ea8524ac00f423","tags":["x_refsource_MISC"]},{"url":"https://github.com/PrivateBin/PrivateBin/releases/tag/2.0.5","name":"https://github.com/PrivateBin/PrivateBin/releases/tag/2.0.5","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.3,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-80","lang":"en","description":"CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-28T20:20:53.934Z"},"source":{"advisory":"GHSA-f2xf-7x3g-4272","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-31T15:21:13.636591Z","id":"CVE-2026-55696","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":"2026-08-31T18:53:53.698Z"}}]}}}