{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-4159", "assignerOrgId": "50d2cd11-d01a-48ed-9441-5bfce9d63b27", "state": "PUBLISHED", "assignerShortName": "wolfSSL", "dateReserved": "2026-03-13T20:37:44.765Z", "datePublished": "2026-03-19T21:17:46.357Z", "dateUpdated": "2026-03-19T21:17:46.357Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "50d2cd11-d01a-48ed-9441-5bfce9d63b27", "shortName": "wolfSSL", "dateUpdated": "2026-03-19T21:17:46.357Z"}, "title": "wc_PKCS7_DecodeEnvelopedData 1 byte out-of-bounds read", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-125", "description": "CWE-125 Out-of-bounds read", "type": "CWE"}]}], "affected": [{"vendor": "wolfSSL", "product": "wolfSSL", "versions": [{"status": "affected", "version": "0", "lessThan": "5.9.0", "versionType": "semver"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "1-byte OOB heap read in wc_PKCS7_DecodeEnvelopedData via zero-length encrypted content. A vulnerability existed in wolfSSL 5.8.4 and earlier, where a 1-byte out-of-bounds heap read in wc_PKCS7_DecodeEnvelopedData could be triggered by a crafted CMS EnvelopedData message with zero-length encrypted content. Note that PKCS7 support is disabled by default.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<p>1-byte OOB heap read in wc_PKCS7_DecodeEnvelopedData via zero-length encrypted content. A vulnerability existed in wolfSSL 5.8.4 and earlier, where a 1-byte out-of-bounds heap read in wc_PKCS7_DecodeEnvelopedData could be triggered by a crafted CMS EnvelopedData message with zero-length encrypted content. Note that PKCS7 support is disabled by default.</p>"}]}], "references": [{"url": "https://github.com/wolfSSL/wolfssl/pull/9945"}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "LOW", "subAvailabilityImpact": "NONE", "exploitMaturity": "PROOF_OF_CONCEPT", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "GREEN", "version": "4.0", "baseSeverity": "LOW", "baseScore": 1.2, "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/U:Green"}}], "credits": [{"lang": "en", "value": "Haruto Kimura (Stella)", "type": "finder"}], "source": {"discovery": "EXTERNAL"}, "x_generator": {"engine": "Vulnogram 1.0.1"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "1-byte OOB heap read in wc_PKCS7_DecodeEnvelopedData via zero-length encrypted content. A vulnerability existed in wolfSSL 5.8.4 and earlier, where a 1-byte out-of-bounds heap read in wc_PKCS7_DecodeEnvelopedData could be triggered by a crafted CMS EnvelopedData message with zero-length encrypted content. Note that PKCS7 support is disabled by default."}], "id": "CVE-2026-4159", "lastModified": "2026-03-20T13:37:50.737", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "LOCAL", "availabilityRequirement": "NOT_DEFINED", "baseScore": 1.2, "baseSeverity": "LOW", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "PROOF_OF_CONCEPT", "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": "GREEN", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/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:Green", "version": "4.0", "vulnAvailabilityImpact": "LOW", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "facts@wolfssl.com", "type": "Secondary"}]}, "published": "2026-03-19T22:16:42.993", "references": [{"source": "facts@wolfssl.com", "url": "https://github.com/wolfSSL/wolfssl/pull/9945"}], "sourceIdentifier": "facts@wolfssl.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-125"}], "source": "facts@wolfssl.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,5.9.0)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "wolfSSL", "source": "cna", "vendor": "wolfSSL"}, "product": "wolfssl", "vendor": "wolfssl"}], "analysis": {"en": {"generated_at": "2026-03-19T22:21:26.439981+00:00", "value": {"mitigation_remediation": ["Upgrade wolfSSL to a version newer than 5.8.4, such as 5.8.5 or later", "If an upgrade is not immediately possible, verify that PKCS7 support remains disabled in the configuration", "Configure network or application-layer controls to reject unexpected CMS EnvelopedData messages with zero\u2011length content", "Keep the wolfSSL library monitored for vendor releases and apply patches as soon as they become available"], "summary": {"action": "Patch", "impact": "Information Disclosure via 1-byte heap read"}, "threat_synthesis": {"affected_systems": "wolfSSL versions 5.8.4 and earlier contain the flaw. The vulnerability is present in builds where PKCS7 support is enabled, while the default configuration disables PKCS7. No other vendors or products are reported as affected.", "description_and_impact": "A crafted CMS EnvelopedData message containing zero\u2011length encrypted content triggers a 1\u2011byte out\u2011of\u2011bounds heap read in the wc_PKCS7_DecodeEnvelopedData function of the wolfSSL library. The read occurs because the function does not properly check bounds when processing the encrypted content. The resulting unwanted memory access may leak a single byte of data from the heap, potentially revealing sensitive information. This weakness is identified as CWE\u2011125 (Out\u2011of\u2011Bounds Read).", "risk_and_exploitability": "The CVSS score of 1.2 indicates low severity, and there is no EPSS score or KEV listing, suggesting limited exploitation evidence. Exploitation requires an attacker to forge a CMS EnvelopedData message with zero\u2011length content, which would be processed by an application using the wolfSSL library. The primary risk is the disclosure of a small amount of memory data; the impact is therefore modest. The attack vector is likely local or via an application that accepts CMS data, and the exploitability is low due to the precise input required and the limited read length."}}}}, "created": "2026-03-20T08:55:48.958159+00:00", "updated": "2026-03-20T11:05:59.661053+00:00", "vendors": ["wolfssl", "wolfssl$PRODUCT$wolfssl"]}