{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-5264", "assignerOrgId": "50d2cd11-d01a-48ed-9441-5bfce9d63b27", "state": "PUBLISHED", "assignerShortName": "wolfSSL", "dateReserved": "2026-03-31T16:56:10.370Z", "datePublished": "2026-04-09T21:43:12.479Z", "dateUpdated": "2026-04-09T21:43:12.479Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "50d2cd11-d01a-48ed-9441-5bfce9d63b27", "shortName": "wolfSSL", "dateUpdated": "2026-04-09T21:43:12.479Z"}, "title": "DTLS 1.3 ACK heap buffer overflow", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-122", "description": "CWE-122 Heap-based Buffer Overflow", "type": "CWE"}]}], "affected": [{"vendor": "wolfSSL", "product": "wolfSSL", "repo": "https://github.com/wolfSSL/wolfssl", "programFiles": ["src/dtls13.c"], "versions": [{"status": "affected", "version": "0", "lessThan": "5.9.1", "versionType": "semver"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "Heap buffer overflow in DTLS 1.3 ACK message processing. A remote attacker can send a crafted DTLS 1.3 ACK message that triggers a heap buffer overflow.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<p>Heap buffer overflow in DTLS 1.3 ACK message processing. A remote attacker can send a crafted DTLS 1.3 ACK message that triggers a heap buffer overflow.</p>"}]}], "references": [{"url": "https://github.com/wolfssl/wolfssl/pull/10076"}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "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": 8.3, "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N"}}], "credits": [{"lang": "en", "value": "Sunwoo Lee, Korea Institute of Energy Technology (KENTECH)", "type": "finder"}, {"lang": "en", "value": "Seunghyun Yoon, Korea Institute of Energy Technology (KENTECH)", "type": "finder"}], "source": {"discovery": "EXTERNAL"}, "x_generator": {"engine": "Vulnogram 1.0.1"}}}}

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{"cveTags": [], "descriptions": [{"lang": "en", "value": "Heap buffer overflow in DTLS 1.3 ACK message processing. A remote attacker can send a crafted DTLS 1.3 ACK message that triggers a heap buffer overflow."}], "id": "CVE-2026-5264", "lastModified": "2026-04-09T22:16:36.790", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 8.3, "baseSeverity": "HIGH", "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": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/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", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "facts@wolfssl.com", "type": "Secondary"}]}, "published": "2026-04-09T22:16:36.790", "references": [{"source": "facts@wolfssl.com", "url": "https://github.com/wolfssl/wolfssl/pull/10076"}], "sourceIdentifier": "facts@wolfssl.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-122"}], "source": "facts@wolfssl.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,5.9.1)"}}], "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": "2026-04-09T23:23:34.356622+00:00", "value": {"mitigation_remediation": ["Apply the latest wolfSSL version that includes the DTLS\u202f1.3 ACK overflow fix.", "If an upgrade is not immediately possible, isolate or harden affected services to block inbound DTLS traffic until a patch can be applied.", "Monitor network traffic for anomalous DTLS ACK packets and report any suspicious activity to the security team."], "summary": {"action": "Immediate Patch", "impact": "Remote Code Execution via Heap Buffer Overflow"}, "threat_synthesis": {"affected_systems": "The vulnerability affects the wolfSSL library as distributed by wolfSSL. No specific product version is listed, but all builds handling DTLS\u202f1.3 are potentially impacted until a patched release is available.", "description_and_impact": "A heap buffer overflow occurs during DTLS\u202f1.3 ACK message processing. The flaw allows a remote participant to send a specially crafted ACK packet that overwrites memory on the heap, potentially enabling arbitrary code execution or processes to crash. The weakness is classified as CWE\u2011122, indicating a classic heap overflow.", "risk_and_exploitability": "The CVSS score of 8.3 shows high severity. The EPSS score is not available, and the flaw is not listed in the CISA KEV catalog. The likely attack vector is remote; an adversary must reach the DTLS endpoint and send a crafted ACK message. No further prerequisites are stated, implying the vulnerability is exploitable in standard use scenarios."}}}}, "created": "2026-04-10T08:36:47.408536+00:00", "updated": "2026-04-10T09:27:44.104241+00:00", "vendors": ["wolfssl", "wolfssl$PRODUCT$wolfssl"]}