{"id":"CVE-2026-49449","state":"PUBLISHED","title":"Joplin: KaTeX `trust:true` enables URL-allowlist bypass leading to NTLMv2 credential theft via UNC path on Windows","description":"Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. From 1.4.0 until 3.7.2, packages/renderer/MdToHtml/rules/katex.ts enables KaTeX's trust option for note content, allowing a note author to place a \\href URL into rendered output without passing Joplin's normal URL allowlist. On Windows, clicking a link whose target is an attacker-controlled UNC path causes pathExists() to initiate SMB authentication and disclose the current user's NTLMv2 challenge-response without a warning. The unfiltered URL can also invoke other registered URL handlers, but the credential disclosure through KaTeX \\href is the distinguishing demonstrated impact. This issue is fixed in version 3.7.2.","publishedAt":"2026-09-21T20:52:11.164Z","updatedAt":"2026-09-28T20:15:24.088Z","severity":{"score":2.5,"label":"Low","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["laurent22 joplin"],"affected":[{"vendor":"laurent22","product":"joplin","versions":[{"version":">= 1.4.0, < 3.7.2","status":"affected"}]}],"references":["https://github.com/laurent22/joplin/security/advisories/GHSA-9m2r-pv96-jxr3","https://github.com/laurent22/joplin/pull/15538","https://github.com/laurent22/joplin/commit/b15472bc9654a72101b34b79c9436b3d450e2c10"],"weaknesses":["CWE-200","CWE-522","CWE-829"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/49xxx/CVE-2026-49449.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-49449","state":"PUBLISHED","datePublished":"2026-09-21T20:52:11.164Z","dateUpdated":"2026-09-28T20:15:24.088Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-05-30T02:43:33.106Z"},"containers":{"cna":{"title":"Joplin: KaTeX `trust:true` enables URL-allowlist bypass leading to NTLMv2 credential theft via UNC path on Windows","descriptions":[{"lang":"en","value":"Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. From 1.4.0 until 3.7.2, packages/renderer/MdToHtml/rules/katex.ts enables KaTeX's trust option for note content, allowing a note author to place a \\href URL into rendered output without passing Joplin's normal URL allowlist. On Windows, clicking a link whose target is an attacker-controlled UNC path causes pathExists() to initiate SMB authentication and disclose the current user's NTLMv2 challenge-response without a warning. The unfiltered URL can also invoke other registered URL handlers, but the credential disclosure through KaTeX \\href is the distinguishing demonstrated impact. This issue is fixed in version 3.7.2."}],"affected":[{"vendor":"laurent22","product":"joplin","versions":[{"version":">= 1.4.0, < 3.7.2","status":"affected"}]}],"references":[{"url":"https://github.com/laurent22/joplin/security/advisories/GHSA-9m2r-pv96-jxr3","name":"https://github.com/laurent22/joplin/security/advisories/GHSA-9m2r-pv96-jxr3","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/laurent22/joplin/pull/15538","name":"https://github.com/laurent22/joplin/pull/15538","tags":["x_refsource_MISC"]},{"url":"https://github.com/laurent22/joplin/commit/b15472bc9654a72101b34b79c9436b3d450e2c10","name":"https://github.com/laurent22/joplin/commit/b15472bc9654a72101b34b79c9436b3d450e2c10","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"LOCAL","availabilityImpact":"NONE","baseScore":2.5,"baseSeverity":"LOW","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-200","lang":"en","description":"CWE-200: Exposure of Sensitive Information to an Unauthorized Actor","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-522","lang":"en","description":"CWE-522: Insufficiently Protected Credentials","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-829","lang":"en","description":"CWE-829: Inclusion of Functionality from Untrusted Control Sphere","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-21T20:52:11.164Z"},"source":{"advisory":"GHSA-9m2r-pv96-jxr3","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/laurent22/joplin/security/advisories/GHSA-9m2r-pv96-jxr3","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-28T20:15:08.128891Z","id":"CVE-2026-49449","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-28T20:15:24.088Z"}}]}}}