CVE-2026-121373

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-121373", "assignerOrgId": "596c5446-0ce5-4ba2-aa66-48b3b757a647", "state": "PUBLISHED", "assignerShortName": "Checkmarx", "dateReserved": "2026-11-03T11:38:38.187Z", "datePublished": "2026-11-04T12:59:22.585Z", "dateUpdated": "2026-11-04T18:20:22.620Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "596c5446-0ce5-4ba2-aa66-48b3b757a647", "shortName": "Checkmarx", "dateUpdated": "2026-11-04T18:14:54.592Z"}, "title": "Symfony: HtmlSanitizer MetaRefreshAttributeSanitizer Matches Only a Narrow Subset of the Browser Refresh Grammar (Incomplete Fix for CVE-2026-48761)", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-186", "description": "CWE-186 Overly restrictive regular expression", "type": "CWE"}]}, {"descriptions": [{"lang": "en", "cweId": "CWE-601", "description": "CWE-601 URL redirection to untrusted site ('open redirect')", "type": "CWE"}]}], "affected": [{"vendor": "sensiolabs", "product": "symfony", "collectionURL": "https://packagist.org/packages/symfony/html-sanitizer", "packageName": "symfony/html-sanitizer", "repo": "https://github.com/symfony/html-sanitizer", "modules": ["Symfony\\Component\\HtmlSanitizer\\Visitor\\AttributeSanitizer\\MetaRefreshAttributeSanitizer"], "versions": [{"status": "affected", "version": "6.1.0", "lessThan": "6.4.50", "versionType": "git"}, {"status": "affected", "version": "7.0.0", "lessThan": "7.4.23", "versionType": "git"}, {"status": "affected", "version": "8.0.0", "lessThan": "8.1.11", "versionType": "git"}], "defaultStatus": "unaffected"}], "cpeApplicability": [{"operator": "OR", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.0", "versionEndExcluding": "6.4.50"}, {"vulnerable": true, "criteria": "cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0.0", "versionEndExcluding": "7.4.23"}, {"vulnerable": true, "criteria": "cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*", "versionStartIncluding": "8.0.0", "versionEndExcluding": "8.1.11"}]}]}], "descriptions": [{"lang": "en", "value": "The Symfony HtmlSanitizer component\u00a0MetaRefreshAttributeSanitizer, introduced to fix\u00a0CVE-2026-48761,\u00a0sanitizes\u00a0the refresh URL of\u00a0content\u00a0attributes of\u00a0meta\u00a0tags 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\u00a06.4.50, 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\u00a0require a broader approach: the separator after the time may be ASCII whitespace alone, with no\u00a0;\u00a0or\u00a0,, and the\u00a0url=\u00a0keyword is optional. Directives the browser honours, but the regular expression misses are returned unchanged, so the attacker URL skips\u00a0UrlSanitizer\u00a0entirely and both\u00a0allowLinkSchemes\u00a0and\u00a0allowLinkHosts\u00a0are defeated for the refresh navigation.\n\n\n\n\nThis is reachable under any configuration that allows\u00a0meta\u00a0with\u00a0http-equiv\u00a0and\u00a0content, including the documented\u00a0allowStaticElements()\u00a0preset.", "supportingMedia": [{"type": "text/html", "base64": false, "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>"}]}], "references": [{"url": "https://github.com/symfony/symfony/security/advisories/GHSA-wm2w-4mgj-vw33", "tags": ["third-party-advisory"]}, {"url": "https://github.com/symfony/symfony/commit/2d4c4fe36200858b91132a95076fff3d9de89d26", "tags": ["patch"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "NONE", "subConfidentialityImpact": "LOW", "vulnIntegrityImpact": "NONE", "subIntegrityImpact": "LOW", "vulnAvailabilityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "version": "4.0", "baseSeverity": "MEDIUM", "baseScore": 5.3, "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"}}], "credits": [{"lang": "en", "value": "Ilia Alshanetsky", "type": "reporter"}, {"lang": "en", "value": "Nicolas Grekas", "type": "remediation developer"}], "source": {"advisory": "GHSA-wm2w-4mgj-vw33", "discovery": "UNKNOWN"}, "x_generator": {"engine": "Vulnogram 1.0.5"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-121373", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-11-04T17:49:00.814730Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-11-04T18:20:22.620Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-121373", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-11-04T17:49:00.814730Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-11-04T18:12:17.662Z"}}], "cna": {"title": "Symfony: HtmlSanitizer MetaRefreshAttributeSanitizer Matches Only a Narrow Subset of the Browser Refresh Grammar (Incomplete Fix for CVE-2026-48761)", "source": {"advisory": "GHSA-wm2w-4mgj-vw33", "discovery": "UNKNOWN"}, "credits": [{"lang": "en", "type": "reporter", "value": "Ilia Alshanetsky"}, {"lang": "en", "type": "remediation developer", "value": "Nicolas Grekas"}], "metrics": [{"format": "CVSS", "cvssV4_0": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 5.3, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "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", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "PASSIVE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "LOW", "vulnIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "vulnConfidentialityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "affected": [{"repo": "https://github.com/symfony/html-sanitizer", "vendor": "sensiolabs", "modules": ["Symfony\\Component\\HtmlSanitizer\\Visitor\\AttributeSanitizer\\MetaRefreshAttributeSanitizer"], "product": "symfony", "versions": [{"status": "affected", "version": "6.1.0", "lessThan": "6.4.50", "versionType": "git"}, {"status": "affected", "version": "7.0.0", "lessThan": "7.4.23", "versionType": "git"}, {"status": "affected", "version": "8.0.0", "lessThan": "8.1.11", "versionType": "git"}], "packageName": "symfony/html-sanitizer", "collectionURL": "https://packagist.org/packages/symfony/html-sanitizer", "defaultStatus": "unaffected"}], "references": [{"url": "https://github.com/symfony/symfony/security/advisories/GHSA-wm2w-4mgj-vw33", "tags": ["third-party-advisory"]}, {"url": "https://github.com/symfony/symfony/commit/2d4c4fe36200858b91132a95076fff3d9de89d26", "tags": ["patch"]}], "x_generator": {"engine": "Vulnogram 1.0.5"}, "descriptions": [{"lang": "en", "value": "The Symfony HtmlSanitizer component\u00a0MetaRefreshAttributeSanitizer, introduced to fix\u00a0CVE-2026-48761,\u00a0sanitizes\u00a0the refresh URL of\u00a0content\u00a0attributes of\u00a0meta\u00a0tags 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\u00a06.4.50, 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\u00a0require a broader approach: the separator after the time may be ASCII whitespace alone, with no\u00a0;\u00a0or\u00a0,, and the\u00a0url=\u00a0keyword is optional. Directives the browser honours, but the regular expression misses are returned unchanged, so the attacker URL skips\u00a0UrlSanitizer\u00a0entirely and both\u00a0allowLinkSchemes\u00a0and\u00a0allowLinkHosts\u00a0are defeated for the refresh navigation.\n\n\n\n\nThis is reachable under any configuration that allows\u00a0meta\u00a0with\u00a0http-equiv\u00a0and\u00a0content, including the documented\u00a0allowStaticElements()\u00a0preset.", "supportingMedia": [{"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>", "base64": false}]}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-186", "description": "CWE-186 Overly restrictive regular expression"}]}, {"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-601", "description": "CWE-601 URL redirection to untrusted site ('open redirect')"}]}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.4.50", "versionStartIncluding": "6.1.0"}, {"criteria": "cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.4.23", "versionStartIncluding": "7.0.0"}, {"criteria": "cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "8.1.11", "versionStartIncluding": "8.0.0"}], "operator": "OR"}], "operator": "OR"}], "providerMetadata": {"orgId": "596c5446-0ce5-4ba2-aa66-48b3b757a647", "shortName": "Checkmarx", "dateUpdated": "2026-11-04T18:14:54.592Z"}}}, "cveMetadata": {"cveId": "CVE-2026-121373", "state": "PUBLISHED", "dateUpdated": "2026-11-04T18:20:22.620Z", "dateReserved": "2026-11-03T11:38:38.187Z", "assignerOrgId": "596c5446-0ce5-4ba2-aa66-48b3b757a647", "datePublished": "2026-11-04T12:59:22.585Z", "assignerShortName": "Checkmarx"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"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"}]}], "source": "596c5446-0ce5-4ba2-aa66-48b3b757a647"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "The Symfony HtmlSanitizer component\u00a0MetaRefreshAttributeSanitizer, introduced to fix\u00a0CVE-2026-48761,\u00a0sanitizes\u00a0the refresh URL of\u00a0content\u00a0attributes of\u00a0meta\u00a0tags 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\u00a06.4.50, 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\u00a0require a broader approach: the separator after the time may be ASCII whitespace alone, with no\u00a0;\u00a0or\u00a0,, and the\u00a0url=\u00a0keyword is optional. Directives the browser honours, but the regular expression misses are returned unchanged, so the attacker URL skips\u00a0UrlSanitizer\u00a0entirely and both\u00a0allowLinkSchemes\u00a0and\u00a0allowLinkHosts\u00a0are defeated for the refresh navigation.\n\n\n\n\nThis is reachable under any configuration that allows\u00a0meta\u00a0with\u00a0http-equiv\u00a0and\u00a0content, including the documented\u00a0allowStaticElements()\u00a0preset."}], "id": "CVE-2026-121373", "lastModified": "2026-11-06T21:40:43.450", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "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/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", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "596c5446-0ce5-4ba2-aa66-48b3b757a647", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-121373", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-11-04T17:49:00.814730Z", "version": "2.0.3"}}]}, "published": "2026-11-04T13:17:27.350", "references": [{"source": "596c5446-0ce5-4ba2-aa66-48b3b757a647", "url": "https://github.com/symfony/symfony/commit/2d4c4fe36200858b91132a95076fff3d9de89d26"}, {"source": "596c5446-0ce5-4ba2-aa66-48b3b757a647", "url": "https://github.com/symfony/symfony/security/advisories/GHSA-wm2w-4mgj-vw33"}], "sourceIdentifier": "596c5446-0ce5-4ba2-aa66-48b3b757a647", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-186"}, {"lang": "en", "value": "CWE-601"}], "source": "596c5446-0ce5-4ba2-aa66-48b3b757a647", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[6.1,6.4.50)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[7,7.4.23)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[8,8.1.11)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "symfony", "source": "cna", "vendor": "sensiolabs"}, "product": "symfony", "vendor": "sensiolabs"}], "created": "2026-11-04T14:45:07.225710+00:00", "updated": "2026-11-04T14:45:07.654760+00:00", "vendors": ["sensiolabs", "sensiolabs$PRODUCT$symfony"]}