{"api_version":"1","generated_at":"2026-11-04T21:59:33+00:00","cve":"CVE-2026-121373","urls":{"html":"https://cve.report/CVE-2026-121373","api":"https://cve.report/api/cve/CVE-2026-121373.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-121373","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-121373"},"summary":{"title":"Symfony: HtmlSanitizer MetaRefreshAttributeSanitizer Matches Only a Narrow Subset of the Browser Refresh Grammar (Incomplete Fix for CVE-2026-48761)","description":"The Symfony HtmlSanitizer component MetaRefreshAttributeSanitizer, introduced to fix CVE-2026-48761, sanitizes the refresh URL of content attributes of meta tags using a regular expression that is too narrow, allowing sanitization to be bypassed, and resulting in potential URL redirection to untrusted sites in Symfony versions 6.1.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11.\n\n\n\n\nThe shared declarative refresh steps in the WHATWG HTML Standard require a broader approach: the separator after the time may be ASCII whitespace alone, with no ; or ,, and the url= keyword is optional. Directives the browser honours, but the regular expression misses are returned unchanged, so the attacker URL skips UrlSanitizer entirely and both allowLinkSchemes and allowLinkHosts are defeated for the refresh navigation.\n\n\n\n\nThis is reachable under any configuration that allows meta with http-equiv and content, including the documented allowStaticElements() preset.","state":"PUBLISHED","assigner":"Checkmarx","published_at":"2026-11-04 13:17:27","updated_at":"2026-11-04 19:17:30"},"problem_types":["CWE-186","CWE-601","CWE-186 CWE-186 Overly restrictive regular expression","CWE-601 CWE-601 URL redirection to untrusted site ('open redirect')"],"metrics":[{"version":"4.0","source":"596c5446-0ce5-4ba2-aa66-48b3b757a647","type":"Secondary","score":"5.3","severity":"MEDIUM","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","data":{"version":"4.0","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","baseScore":5.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}},{"version":"4.0","source":"CNA","type":"CVSS","score":"5.3","severity":"MEDIUM","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","data":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":5.3,"baseSeverity":"MEDIUM","exploitMaturity":"NOT_DEFINED","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","userInteraction":"PASSIVE","valueDensity":"NOT_DEFINED","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","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"}}],"references":[{"url":"https://github.com/symfony/symfony/security/advisories/GHSA-wm2w-4mgj-vw33","name":"https://github.com/symfony/symfony/security/advisories/GHSA-wm2w-4mgj-vw33","refsource":"596c5446-0ce5-4ba2-aa66-48b3b757a647","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/symfony/symfony/commit/2d4c4fe36200858b91132a95076fff3d9de89d26","name":"https://github.com/symfony/symfony/commit/2d4c4fe36200858b91132a95076fff3d9de89d26","refsource":"596c5446-0ce5-4ba2-aa66-48b3b757a647","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-121373","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121373","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"sensiolabs","product":"symfony","version":"affected 6.1.0 6.4.50 git","platforms":[]},{"source":"CNA","vendor":"sensiolabs","product":"symfony","version":"affected 7.0.0 7.4.23 git","platforms":[]},{"source":"CNA","vendor":"sensiolabs","product":"symfony","version":"affected 8.0.0 8.1.11 git","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[{"source":"CNA","value":"Ilia Alshanetsky","lang":"en"},{"source":"CNA","value":"Nicolas Grekas","lang":"en"}],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"other":{"content":{"id":"CVE-2026-121373","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2026-11-04T17:49:00.814730Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-11-04T18:20:22.620Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"collectionURL":"https://packagist.org/packages/symfony/html-sanitizer","defaultStatus":"unaffected","modules":["Symfony\\Component\\HtmlSanitizer\\Visitor\\AttributeSanitizer\\MetaRefreshAttributeSanitizer"],"packageName":"symfony/html-sanitizer","product":"symfony","repo":"https://github.com/symfony/html-sanitizer","vendor":"sensiolabs","versions":[{"lessThan":"6.4.50","status":"affected","version":"6.1.0","versionType":"git"},{"lessThan":"7.4.23","status":"affected","version":"7.0.0","versionType":"git"},{"lessThan":"8.1.11","status":"affected","version":"8.0.0","versionType":"git"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*","versionEndExcluding":"6.4.50","versionStartIncluding":"6.1.0","vulnerable":true},{"criteria":"cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*","versionEndExcluding":"7.4.23","versionStartIncluding":"7.0.0","vulnerable":true},{"criteria":"cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*","versionEndExcluding":"8.1.11","versionStartIncluding":"8.0.0","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"OR"}],"credits":[{"lang":"en","type":"reporter","value":"Ilia Alshanetsky"},{"lang":"en","type":"remediation developer","value":"Nicolas Grekas"}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<div>The Symfony HtmlSanitizer component&nbsp;<code>MetaRefreshAttributeSanitizer</code><span>, introduced to fix&nbsp;</span><span>CVE-2026-48761</span>,&nbsp;<span>s</span><span>anitizes&nbsp;</span><span>the refresh URL of&nbsp;</span><code>content</code><span>&nbsp;attributes of&nbsp;</span><code>meta</code><span>&nbsp;tags using a regular expression that is too narrow, allowing sanitization to be bypassed, and resulting in potential URL redirection to untrusted sites in Symfony versions 6.1.x prior to&nbsp;</span><span>6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11.</span></div><div><span><br></span></div><div>The shared declarative refresh steps in the WHATWG HTML Standard&nbsp;require a broader approach: the separator after the time may be ASCII whitespace alone, with no&nbsp;<code>;</code>&nbsp;or&nbsp;<code>,</code>, and the&nbsp;<code>url=</code>&nbsp;keyword is optional. Directives the browser honours, but the regular expression misses are returned unchanged, so the attacker URL skips&nbsp;<code>UrlSanitizer</code>&nbsp;entirely and both&nbsp;<code>allowLinkSchemes</code>&nbsp;and&nbsp;<code>allowLinkHosts</code>&nbsp;are defeated for the refresh navigation.</div><div><br></div><div>This is reachable under any configuration that allows&nbsp;<code>meta</code>&nbsp;with&nbsp;<code>http-equiv</code>&nbsp;and&nbsp;<code>content</code>, including the documented&nbsp;<code>allowStaticElements()</code>&nbsp;preset.</div>"}],"value":"The Symfony HtmlSanitizer component MetaRefreshAttributeSanitizer, introduced to fix CVE-2026-48761, sanitizes the refresh URL of content attributes of meta tags using a regular expression that is too narrow, allowing sanitization to be bypassed, and resulting in potential URL redirection to untrusted sites in Symfony versions 6.1.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11.\n\n\n\n\nThe shared declarative refresh steps in the WHATWG HTML Standard require a broader approach: the separator after the time may be ASCII whitespace alone, with no ; or ,, and the url= keyword is optional. Directives the browser honours, but the regular expression misses are returned unchanged, so the attacker URL skips UrlSanitizer entirely and both allowLinkSchemes and allowLinkHosts are defeated for the refresh navigation.\n\n\n\n\nThis is reachable under any configuration that allows meta with http-equiv and content, including the documented allowStaticElements() preset."}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":5.3,"baseSeverity":"MEDIUM","exploitMaturity":"NOT_DEFINED","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","userInteraction":"PASSIVE","valueDensity":"NOT_DEFINED","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","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-186","description":"CWE-186 Overly restrictive regular expression","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-601","description":"CWE-601 URL redirection to untrusted site ('open redirect')","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-11-04T18:14:54.592Z","orgId":"596c5446-0ce5-4ba2-aa66-48b3b757a647","shortName":"Checkmarx"},"references":[{"tags":["third-party-advisory"],"url":"https://github.com/symfony/symfony/security/advisories/GHSA-wm2w-4mgj-vw33"},{"tags":["patch"],"url":"https://github.com/symfony/symfony/commit/2d4c4fe36200858b91132a95076fff3d9de89d26"}],"source":{"advisory":"GHSA-wm2w-4mgj-vw33","discovery":"UNKNOWN"},"title":"Symfony: HtmlSanitizer MetaRefreshAttributeSanitizer Matches Only a Narrow Subset of the Browser Refresh Grammar (Incomplete Fix for CVE-2026-48761)","x_generator":{"engine":"Vulnogram 1.0.5"}}},"cveMetadata":{"assignerOrgId":"596c5446-0ce5-4ba2-aa66-48b3b757a647","assignerShortName":"Checkmarx","cveId":"CVE-2026-121373","datePublished":"2026-11-04T12:59:22.585Z","dateReserved":"2026-11-03T11:38:38.187Z","dateUpdated":"2026-11-04T18:20:22.620Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-11-04 13:17:27","lastModifiedDate":"2026-11-04 19:17:30","problem_types":["CWE-186","CWE-601","CWE-186 CWE-186 Overly restrictive regular expression","CWE-601 CWE-601 URL redirection to untrusted site ('open redirect')"],"metrics":{"cvssMetricV40":[{"source":"596c5446-0ce5-4ba2-aa66-48b3b757a647","type":"Secondary","cvssData":{"version":"4.0","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","baseScore":5.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-11-04T17:49:00.814730Z","id":"CVE-2026-121373","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"121373","Ordinal":"1","Title":"Symfony: HtmlSanitizer MetaRefreshAttributeSanitizer Matches Onl","CVE":"CVE-2026-121373","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"121373","Ordinal":"1","NoteData":"The Symfony HtmlSanitizer component MetaRefreshAttributeSanitizer, introduced to fix CVE-2026-48761, sanitizes the refresh URL of content attributes of meta tags using a regular expression that is too narrow, allowing sanitization to be bypassed, and resulting in potential URL redirection to untrusted sites in Symfony versions 6.1.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11.\n\n\n\n\nThe shared declarative refresh steps in the WHATWG HTML Standard require a broader approach: the separator after the time may be ASCII whitespace alone, with no ; or ,, and the url= keyword is optional. Directives the browser honours, but the regular expression misses are returned unchanged, so the attacker URL skips UrlSanitizer entirely and both allowLinkSchemes and allowLinkHosts are defeated for the refresh navigation.\n\n\n\n\nThis is reachable under any configuration that allows meta with http-equiv and content, including the documented allowStaticElements() preset.","Type":"Description","Title":"Symfony: HtmlSanitizer MetaRefreshAttributeSanitizer Matches Onl"}]}}}