{"id":"CVE-2026-3549","state":"PUBLISHED","title":"ECH parsing heap buffer overflow","description":"Heap Overflow in TLS 1.3 ECH parsing. An integer underflow existed in ECH extension parsing logic when calculating a buffer length, which resulted in writing beyond the bounds of an allocated buffer. Note that in wolfSSL, ECH is off by default, and the ECH standard is still evolving.","publishedAt":"2026-03-19T20:09:27.036Z","updatedAt":"2026-03-24T01:38:13.951Z","severity":{"score":8.3,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:H/SC:L/SI:L/SA:L","source":"wolfSSL"},"assigner":"wolfSSL","products":["wofSSL wolfSSL"],"affected":[{"vendor":"wofSSL","product":"wolfSSL","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"5.9.0","versionType":"semver"}]}],"references":["https://github.com/wolfSSL/wolfssl/pull/9817"],"weaknesses":["CWE-122"],"ingestedAt":"2026-10-29T20:11:50.837Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/3xxx/CVE-2026-3549.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-3549","state":"PUBLISHED","datePublished":"2026-03-19T20:09:27.036Z","dateUpdated":"2026-03-24T01:38:13.951Z","assignerShortName":"wolfSSL","assignerOrgId":"50d2cd11-d01a-48ed-9441-5bfce9d63b27","dateReserved":"2026-03-04T18:44:13.820Z"},"containers":{"cna":{"title":"ECH parsing heap buffer overflow","descriptions":[{"lang":"en","value":"Heap Overflow in TLS 1.3 ECH parsing. An integer underflow existed in ECH extension parsing logic when calculating a buffer length, which resulted in writing beyond the bounds of an allocated buffer. Note that in wolfSSL, ECH is off by default, and the ECH standard is still evolving."}],"affected":[{"vendor":"wofSSL","product":"wolfSSL","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"5.9.0","versionType":"semver"}]}],"references":[{"url":"https://github.com/wolfSSL/wolfssl/pull/9817"}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"LOW","subConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","subIntegrityImpact":"LOW","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"LOW","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:L/VI:L/VA:H/SC:L/SI:L/SA:L"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-122","lang":"en","description":"CWE-122 Heap-based buffer overflow","type":"CWE"}]}],"providerMetadata":{"shortName":"wolfSSL","orgId":"50d2cd11-d01a-48ed-9441-5bfce9d63b27","dateUpdated":"2026-03-19T20:09:27.036Z"},"credits":[{"lang":"en","value":"Oleh Konko for independently reporting after internal wolfSSL findings and testing wolfSSL's fix","type":"other"}],"source":{"discovery":"INTERNAL"},"x_generator":{"engine":"Vulnogram 1.0.1"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-24T01:37:47.102762Z","id":"CVE-2026-3549","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-03-24T01:38:13.951Z"}}]}}}