{"id":"CVE-2026-93990","aliases":[],"cve":{"records":[{"id":"CVE-2026-93990","source":"VulnCheck","state":"PUBLISHED","reasons":[],"replacements":[],"disputed":false,"unsupportedWhenAssigned":false,"reserved":"2026-09-19T10:55:49.093Z","published":"2026-09-19T22:58:11.224Z","modified":"2026-11-10T12:49:54.993Z"}],"publishers":[{"name":"VulnCheck","role":"CNA","organizationId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","modified":"2026-11-08T14:09:22.450Z"},{"name":"CISA-ADP","role":"ADP","organizationId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","modified":"2026-09-21T15:13:37.622Z"},{"name":"siemens-SADP","role":"ADP","organizationId":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","modified":"2026-11-10T12:49:54.993Z"}],"references":[{"url":"https://github.com/libexpat/libexpat/pull/1282","tags":["issue-tracking","patch"],"source":"VulnCheck"},{"url":"https://github.com/libexpat/libexpat/commit/ff6e1d7e750bbe245178f51a47a965dc8342861a","tags":["patch"],"source":"VulnCheck"},{"url":"https://github.com/libexpat/libexpat/releases/tag/R_2_8_5","tags":["release-notes"],"source":"VulnCheck"},{"url":"https://blog.hartwork.org/posts/expat-2-8-5-released/","tags":["vendor-advisory"],"source":"VulnCheck"},{"url":"https://github.com/libexpat/libexpat","tags":["product"],"source":"VulnCheck"},{"url":"https://www.vulncheck.com/advisories/expat-through-2.8.4-malformed-utf-16-acceptance-via-unchecked-surrogate","tags":["third-party-advisory"],"source":"VulnCheck"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-457936.html","tags":[],"source":"siemens-SADP"}],"weaknesses":[{"id":"CWE-176","description":"Improper Handling of Unicode Encoding","source":"VulnCheck"}],"applicability":[{"source":"VulnCheck","statements":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*","versionEndExcluding":"2.8.5"}]}]}]}],"prioritization":[{"source":"CISA-ADP","type":"SSVC","role":"CISA Coordinator","timestamp":"2026-09-21T15:10:43.564847Z","decisions":[{"name":"Exploitation","value":"none"},{"name":"Automatable","value":"yes"},{"name":"Technical Impact","value":"partial"}]}]},"title":"Expat before 2.8.5 Malformed UTF-16 Acceptance via Unchecked Surrogate","titleSource":"VulnCheck","descriptionSource":"VulnCheck","description":"Expat before 2.8.5 fails to validate that a high surrogate in UTF-16 input is followed by a low surrogate, allowing malformed UTF-16 sequences to be accepted. Attackers can supply UTF-16 encoded XML containing lone high surrogates that consume the following code unit, causing Expat to pass unpaired surrogates to applications built with XML_UNICODE and to silently replace input characters in other builds.","score":8.7,"severity":"high","published":"2026-09-19T22:58:11.224Z","modified":"2026-11-10T12:49:54.993Z","withdrawn":false,"knownExploited":false,"affected":[],"products":[{"vendor":"libexpat","name":"libexpat","platforms":[],"versions":[{"version":"0","status":"affected","lessThan":"2.8.5","versionType":"semver"},{"version":"2.8.5","status":"unaffected","versionType":"semver"}],"defaultStatus":"unaffected","packageURL":"pkg:github/libexpat/libexpat","cpes":[],"source":"VulnCheck","url":"https://www.cve.org/CVERecord?id=CVE-2026-93990"},{"vendor":"Siemens","name":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)","platforms":[],"versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}],"defaultStatus":"unknown","cpes":[],"source":"siemens-SADP","url":"https://www.cve.org/CVERecord?id=CVE-2026-93990"},{"vendor":"Siemens","name":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)","platforms":[],"versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}],"defaultStatus":"unknown","cpes":[],"source":"siemens-SADP","url":"https://www.cve.org/CVERecord?id=CVE-2026-93990"},{"vendor":"Siemens","name":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)","platforms":[],"versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}],"defaultStatus":"unknown","cpes":[],"source":"siemens-SADP","url":"https://www.cve.org/CVERecord?id=CVE-2026-93990"},{"vendor":"Siemens","name":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)","platforms":[],"versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}],"defaultStatus":"unknown","cpes":[],"source":"siemens-SADP","url":"https://www.cve.org/CVERecord?id=CVE-2026-93990"},{"vendor":"Siemens","name":"SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)","platforms":[],"versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}],"defaultStatus":"unknown","cpes":[],"source":"siemens-SADP","url":"https://www.cve.org/CVERecord?id=CVE-2026-93990"}],"remediation":[],"references":["https://github.com/libexpat/libexpat/pull/1282","https://github.com/libexpat/libexpat/commit/ff6e1d7e750bbe245178f51a47a965dc8342861a","https://github.com/libexpat/libexpat/releases/tag/R_2_8_5","https://blog.hartwork.org/posts/expat-2-8-5-released/","https://github.com/libexpat/libexpat","https://www.vulncheck.com/advisories/expat-through-2.8.4-malformed-utf-16-acceptance-via-unchecked-surrogate","https://cert-portal.siemens.com/productcert/html/ssa-457936.html"],"sources":[{"name":"CVE","id":"CVE-2026-93990","modified":"2026-11-10T12:49:54.993Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-93990"}],"assessments":[{"source":"VulnCheck","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","score":8.7},{"source":"VulnCheck","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5}],"sourceAffected":[],"observedAt":"2026-11-10T13:03:17.894Z","kev":{"status":"not-listed","checkedAt":"2026-11-14T23:30:30.969Z"},"coverage":[{"source":"NVD","status":"available","checkedAt":"2026-11-08T14:35:32.900Z","attemptedAt":"2026-11-08T14:35:32.900Z"},{"source":"GHSA","status":"available","checkedAt":"2026-11-08T14:35:33.121Z","attemptedAt":"2026-11-08T14:35:33.121Z"},{"source":"EUVD","status":"available","checkedAt":"2026-11-08T14:35:33.628Z","attemptedAt":"2026-11-08T14:35:33.628Z"},{"source":"EPSS","status":"available","checkedAt":"2026-11-08T14:35:32.873Z","attemptedAt":"2026-11-08T14:35:32.873Z"}],"evidence":[{"source":"FIRST EPSS","id":"CVE-2026-93990","url":"https://www.first.org/epss/","probability":0.00403,"percentile":0.34853,"date":"2026-11-08","checkedAt":"2026-11-08T14:35:32.873Z"},{"source":"NVD","id":"CVE-2026-93990","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93990","modified":"2026-09-28T17:17:53.037","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/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","checkedAt":"2026-11-08T14:35:32.900Z"},{"source":"NVD","id":"CVE-2026-93990","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93990","modified":"2026-09-28T17:17:53.037","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","checkedAt":"2026-11-08T14:35:32.900Z"},{"source":"GitHub Advisory Database","id":"GHSA-rfp9-ffqc-h4x8","url":"https://github.com/advisories/GHSA-rfp9-ffqc-h4x8","modified":"2026-09-28T18:32:14Z","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","checkedAt":"2026-11-08T14:35:33.121Z"},{"source":"ENISA EUVD","id":"EUVD-2026-83618","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-83618","modified":"Sep 28, 2026, 4:11:06 PM","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","checkedAt":"2026-11-08T14:35:33.628Z"}],"aiSummary":{"text":"Expat before 2.8.5 fails to validate UTF-16 input, allowing malformed sequences to be accepted. Attackers can supply malformed UTF-16 encoded XML. The impact is silent replacement of input characters in some builds.","model":"@cf/meta/llama-3.3-70b-instruct-fp8-fast","generatedAt":"2026-11-10T13:06:03.927Z","sources":[{"name":"CVE","url":"https://www.cve.org/CVERecord?id=CVE-2026-93990"}]}}