{"id":"CVE-2026-55090","state":"PUBLISHED","title":"Etherpad: Stored XSS in HTML export via unescaped attribute-pool values","description":"Etherpad is a real-time collaborative editor. Prior to 3.3.0, getHTMLFromAtext in src/node/utils/ExportHtml.ts interpolates values from the exportHtmlAdditionalTagsWithData plugin hook into span data attributes without HTML attribute escaping. A pad editor can place an attacker-controlled value into the attribute pool through moveOpsToNewPool and AttributePool.putAttrib. When a bundled plugin such as ep_font_color or ep_font_size registers the hook, opening the resulting HTML export causes the value to execute as stored cross-site scripting in the Etherpad origin. This issue is fixed in version 3.3.0.","publishedAt":"2026-08-19T19:32:17.607Z","updatedAt":"2026-08-20T12:39:30.300Z","severity":{"score":5.3,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["ether etherpad"],"affected":[{"vendor":"ether","product":"etherpad","versions":[{"version":"< 3.3.0","status":"affected"}]}],"references":["https://github.com/ether/etherpad/security/advisories/GHSA-2jp7-wwpg-3p9w","https://github.com/ether/etherpad/pull/7905","https://github.com/ether/etherpad/commit/86c56cf827dd6e5ff1b6cd3760f87adc47f58bb1","https://github.com/ether/etherpad/releases/tag/v3.3.0"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55090.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55090","state":"PUBLISHED","datePublished":"2026-08-19T19:32:17.607Z","dateUpdated":"2026-08-20T12:39:30.300Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-16T14:41:54.578Z"},"containers":{"cna":{"title":"Etherpad: Stored XSS in HTML export via unescaped attribute-pool values","descriptions":[{"lang":"en","value":"Etherpad is a real-time collaborative editor. Prior to 3.3.0, getHTMLFromAtext in src/node/utils/ExportHtml.ts interpolates values from the exportHtmlAdditionalTagsWithData plugin hook into span data attributes without HTML attribute escaping. A pad editor can place an attacker-controlled value into the attribute pool through moveOpsToNewPool and AttributePool.putAttrib. When a bundled plugin such as ep_font_color or ep_font_size registers the hook, opening the resulting HTML export causes the value to execute as stored cross-site scripting in the Etherpad origin. This issue is fixed in version 3.3.0."}],"affected":[{"vendor":"ether","product":"etherpad","versions":[{"version":"< 3.3.0","status":"affected"}]}],"references":[{"url":"https://github.com/ether/etherpad/security/advisories/GHSA-2jp7-wwpg-3p9w","name":"https://github.com/ether/etherpad/security/advisories/GHSA-2jp7-wwpg-3p9w","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/ether/etherpad/pull/7905","name":"https://github.com/ether/etherpad/pull/7905","tags":["x_refsource_MISC"]},{"url":"https://github.com/ether/etherpad/commit/86c56cf827dd6e5ff1b6cd3760f87adc47f58bb1","name":"https://github.com/ether/etherpad/commit/86c56cf827dd6e5ff1b6cd3760f87adc47f58bb1","tags":["x_refsource_MISC"]},{"url":"https://github.com/ether/etherpad/releases/tag/v3.3.0","name":"https://github.com/ether/etherpad/releases/tag/v3.3.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","subAvailabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","version":"4.0"}}],"problemTypes":[{"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":"2026-08-19T19:32:17.607Z"},"source":{"advisory":"GHSA-2jp7-wwpg-3p9w","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-20T12:37:42.746223Z","id":"CVE-2026-55090","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":"2026-08-20T12:39:30.300Z"}}]}}}