{"id":"CVE-2026-71502","state":"PUBLISHED","title":"Unauthenticated Stored Vue Template Injection Leads to Cross-Site Scripting in CTI-Transmute","description":"CTI-Transmute contains a stored cross-site scripting vulnerability caused by insufficient neutralization of Vue template expression delimiters in server-rendered user-controlled data.\n\nAn unauthenticated attacker can create a public conversion whose name or description contains a malicious Vue expression using the application's configured [[ ... ]] delimiters. User profile names may provide an additional injection vector. Although Jinja HTML escaping is applied, the resulting value is subsequently included in a DOM region compiled by Vue.\n\nVue interprets the attacker-controlled value as a template expression rather than ordinary text. By accessing the JavaScript Function constructor from within the expression, an attacker can execute arbitrary JavaScript in the security context of the CTI-Transmute origin. The application's nonce-based Content Security Policy does not prevent exploitation because the Vue runtime compiler requires the unsafe-eval policy exception.\n\nThe malicious payload is stored by the application and executed whenever another user opens an affected page, such as the public conversion detail page. The victim may be a normal user or an administrator. Successful exploitation could allow the attacker to:\n\n  *  Access data available to the victim through the application.\n  *  Extract API keys, tokens, or other sensitive information exposed to the page.\n  *  Perform authenticated actions using the victim's session.\n  *  Modify conversions or other application data.\n  *  Escalate the impact by targeting an administrator.\n\n\nA demonstrated payload can use [].constructor.constructor(...) to obtain the JavaScript Function constructor and execute arbitrary code. The regression tests also show that a short first-stage payload could retrieve an uncapped conversion description and evaluate a larger second-stage payload.\n\nThe patch addresses the vulnerability by registering a global Jinja finalize hook that inserts a zero-width Unicode word joiner inside every Vue delimiter found in server-rendered values. This prevents Vue from recognizing the values as template expressions while preserving their visible representation.","publishedAt":"2026-08-06T20:30:04.442Z","updatedAt":"2026-08-08T21:05:36.527Z","severity":{"score":5.1,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N","source":"CIRCL"},"assigner":"CIRCL","products":["misp cti-transmute"],"affected":[{"vendor":"misp","product":"cti-transmute","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"1.4.0","versionType":"semver"}],"repo":"https://github.com/MISP/cti-transmute"}],"references":["https://github.com/MISP/cti-transmute/commit/ecfdaef63860a071c6f07afd30156ca77a77ad2b","https://github.com/MISP/cti-transmute/commit/522fa8ff8223b12a6128ea3fc2344a77b7b9108d","https://github.com/MISP/cti-transmute/commit/ad8bf2b8031491cefb552314ef7ff6f4148ca95a","https://github.com/MISP/cti-transmute/commit/4f43c9181a00262bec2a6dfbc9ff9c50d534e918"],"weaknesses":["CWE-79","CWE-1336"],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/71xxx/CVE-2026-71502.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-71502","state":"PUBLISHED","datePublished":"2026-08-06T20:30:04.442Z","dateUpdated":"2026-08-08T21:05:36.527Z","assignerShortName":"CIRCL","assignerOrgId":"5a6e4751-2f3f-4070-9419-94fb35b644e8","dateReserved":"2026-08-06T20:29:59.894Z"},"containers":{"cna":{"title":"Unauthenticated Stored Vue Template Injection Leads to Cross-Site Scripting in CTI-Transmute","descriptions":[{"lang":"en","value":"CTI-Transmute contains a stored cross-site scripting vulnerability caused by insufficient neutralization of Vue template expression delimiters in server-rendered user-controlled data.\n\nAn unauthenticated attacker can create a public conversion whose name or description contains a malicious Vue expression using the application's configured [[ ... ]] delimiters. User profile names may provide an additional injection vector. Although Jinja HTML escaping is applied, the resulting value is subsequently included in a DOM region compiled by Vue.\n\nVue interprets the attacker-controlled value as a template expression rather than ordinary text. By accessing the JavaScript Function constructor from within the expression, an attacker can execute arbitrary JavaScript in the security context of the CTI-Transmute origin. The application's nonce-based Content Security Policy does not prevent exploitation because the Vue runtime compiler requires the unsafe-eval policy exception.\n\nThe malicious payload is stored by the application and executed whenever another user opens an affected page, such as the public conversion detail page. The victim may be a normal user or an administrator. Successful exploitation could allow the attacker to:\n\n  *  Access data available to the victim through the application.\n  *  Extract API keys, tokens, or other sensitive information exposed to the page.\n  *  Perform authenticated actions using the victim's session.\n  *  Modify conversions or other application data.\n  *  Escalate the impact by targeting an administrator.\n\n\nA demonstrated payload can use [].constructor.constructor(...) to obtain the JavaScript Function constructor and execute arbitrary code. The regression tests also show that a short first-stage payload could retrieve an uncapped conversion description and evaluate a larger second-stage payload.\n\nThe patch addresses the vulnerability by registering a global Jinja finalize hook that inserts a zero-width Unicode word joiner inside every Vue delimiter found in server-rendered values. This prevents Vue from recognizing the values as template expressions while preserving their visible representation."}],"affected":[{"vendor":"misp","product":"cti-transmute","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"1.4.0","versionType":"semver"}],"repo":"https://github.com/MISP/cti-transmute"}],"references":[{"url":"https://github.com/MISP/cti-transmute/commit/ecfdaef63860a071c6f07afd30156ca77a77ad2b","tags":["patch"]},{"url":"https://github.com/MISP/cti-transmute/commit/522fa8ff8223b12a6128ea3fc2344a77b7b9108d","tags":["patch"]},{"url":"https://github.com/MISP/cti-transmute/commit/ad8bf2b8031491cefb552314ef7ff6f4148ca95a","tags":["patch"]},{"url":"https://github.com/MISP/cti-transmute/commit/4f43c9181a00262bec2a6dfbc9ff9c50d534e918","tags":["patch"]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":5.1,"baseSeverity":"MEDIUM","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","userInteraction":"ACTIVE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","description":"CWE-79 Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting')","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-1336","description":"CWE-1336","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"CIRCL","orgId":"5a6e4751-2f3f-4070-9419-94fb35b644e8","dateUpdated":"2026-08-08T21:05:36.527Z"},"credits":[{"lang":"en","type":"finder","value":"Jeroen Pinoy"},{"lang":"en","type":"remediation developer","value":"Christian Studer"}],"impacts":[{"capecId":"CAPEC-63","descriptions":[{"lang":"en","value":"CAPEC-63 Cross-Site Scripting (XSS)"}]}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 0.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-07T13:57:26.854958Z","id":"CVE-2026-71502","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":"2026-08-07T13:57:37.626Z"}}]}}}