{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-5500","assignerOrgId":"50d2cd11-d01a-48ed-9441-5bfce9d63b27","state":"PUBLISHED","assignerShortName":"wolfSSL","dateReserved":"2026-04-03T15:33:05.734Z","datePublished":"2026-04-10T03:10:25.671Z","dateUpdated":"2026-04-10T13:42:28.091Z"},"containers":{"cna":{"providerMetadata":{"orgId":"50d2cd11-d01a-48ed-9441-5bfce9d63b27","shortName":"wolfSSL","dateUpdated":"2026-04-10T03:10:25.671Z"},"title":"Improper Validation of AES-GCM Authentication Tag Length in PKCS#7 Envelope Allows Authentication Bypass","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-20","description":"CWE-20 Improper input validation","type":"CWE"}]}],"affected":[{"vendor":"wolfSSL","product":"wolfSSL","modules":["wc_PKCS7_DecodeAuthEnvelopedData"],"programFiles":["wolfcrypt/src/pkcs7.c"],"versions":[{"status":"affected","version":"0","lessThanOrEqual":"5.9.0","versionType":"semver"}],"defaultStatus":"unaffected"}],"descriptions":[{"lang":"en","value":"wolfSSL's wc_PKCS7_DecodeAuthEnvelopedData() does not properly sanitize the AES-GCM authentication tag length received and has no lower bounds check. A man-in-the-middle can therefore truncate the mac field from 16 bytes to 1 byte, reducing the tag check from 2⁻¹²⁸ to 2⁻⁸.","supportingMedia":[{"type":"text/html","base64":false,"value":"wolfSSL's wc_PKCS7_DecodeAuthEnvelopedData() does not properly sanitize the AES-GCM authentication tag length received and has no lower bounds check. A man-in-the-middle can therefore truncate the mac field from 16 bytes to 1 byte, reducing the tag check from 2⁻¹²⁸ to 2⁻⁸."}]}],"references":[{"url":"https://github.com/wolfSSL/wolfssl/pull/10102"}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"NONE","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":"HIGH","baseScore":8.7,"vectorString":"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"}}],"credits":[{"lang":"en","value":"Calif.io in collaboration with Claude and Anthropic Research","type":"finder"}],"source":{"discovery":"EXTERNAL"},"x_generator":{"engine":"Vulnogram 1.0.1"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-10T13:42:21.317016Z","id":"CVE-2026-5500","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-04-10T13:42:28.091Z"}}]}}