{"api_version":"1","generated_at":"2026-04-15T21:29:28+00:00","cve":"CVE-2026-34743","urls":{"html":"https://cve.report/CVE-2026-34743","api":"https://cve.report/api/cve/CVE-2026-34743.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-34743","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-34743"},"summary":{"title":"XZ Utils: Buffer overflow in lzma_index_append()","description":"XZ Utils provide a general-purpose data-compression library plus command-line tools. Prior to version 5.8.3, if lzma_index_decoder() was used to decode an Index that contained no Records, the resulting lzma_index was left in a state where where a subsequent lzma_index_append() would allocate too little memory, and a buffer overflow would occur. This issue has been patched in version 5.8.3.","state":"PUBLISHED","assigner":"GitHub_M","published_at":"2026-04-02 19:21:33","updated_at":"2026-04-15 17:33:17"},"problem_types":["CWE-122","CWE-122 CWE-122: Heap-based Buffer Overflow"],"metrics":[{"version":"4.0","source":"security-advisories@github.com","type":"Secondary","score":"1.7","severity":"LOW","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/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","data":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/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","baseScore":1.7,"baseSeverity":"LOW","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"LOW","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"UNREPORTED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}},{"version":"4.0","source":"CNA","type":"DECLARED","score":"1.7","severity":"LOW","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U","data":{"attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":1.7,"baseSeverity":"LOW","privilegesRequired":"NONE","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U","version":"4.0","vulnAvailabilityImpact":"LOW","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE"}},{"version":"3.1","source":"nvd@nist.gov","type":"Primary","score":"5.3","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","baseScore":5.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"LOW"}}],"references":[{"url":"https://github.com/tukaani-project/xz/security/advisories/GHSA-x872-m794-cxhv","name":"https://github.com/tukaani-project/xz/security/advisories/GHSA-x872-m794-cxhv","refsource":"security-advisories@github.com","tags":["Vendor Advisory"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/tukaani-project/xz/commit/c8c22869e780ff57c96b46939c3d79ff99395f87","name":"https://github.com/tukaani-project/xz/commit/c8c22869e780ff57c96b46939c3d79ff99395f87","refsource":"security-advisories@github.com","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"http://www.openwall.com/lists/oss-security/2026/03/31/13","name":"http://www.openwall.com/lists/oss-security/2026/03/31/13","refsource":"af854a3a-2127-422b-91ae-364da2661108","tags":["Mailing List","Patch","Third Party Advisory"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/tukaani-project/xz/releases/tag/v5.8.3","name":"https://github.com/tukaani-project/xz/releases/tag/v5.8.3","refsource":"security-advisories@github.com","tags":["Product","Release Notes"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-34743","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34743","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"tukaani-project","product":"xz","version":"affected < 5.8.3","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2026","cve_id":"34743","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"tukaani","cpe5":"xz","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"34743","cve":"CVE-2026-34743","epss":"0.000420000","percentile":"0.128850000","score_date":"2026-04-07","updated_at":"2026-04-08 00:03:39"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"providerMetadata":{"dateUpdated":"2026-04-02T19:24:10.537Z","orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE"},"references":[{"url":"http://www.openwall.com/lists/oss-security/2026/03/31/13"}],"title":"CVE Program Container"},{"metrics":[{"other":{"content":{"id":"CVE-2026-34743","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2026-04-03T12:58:58.398176Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-04-03T12:59:06.096Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"product":"xz","vendor":"tukaani-project","versions":[{"status":"affected","version":"< 5.8.3"}]}],"descriptions":[{"lang":"en","value":"XZ Utils provide a general-purpose data-compression library plus command-line tools. Prior to version 5.8.3, if lzma_index_decoder() was used to decode an Index that contained no Records, the resulting lzma_index was left in a state where where a subsequent lzma_index_append() would allocate too little memory, and a buffer overflow would occur. This issue has been patched in version 5.8.3."}],"metrics":[{"cvssV4_0":{"attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":1.7,"baseSeverity":"LOW","privilegesRequired":"NONE","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U","version":"4.0","vulnAvailabilityImpact":"LOW","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-122","description":"CWE-122: Heap-based Buffer Overflow","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-04-02T18:36:37.450Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M"},"references":[{"name":"https://github.com/tukaani-project/xz/security/advisories/GHSA-x872-m794-cxhv","tags":["x_refsource_CONFIRM"],"url":"https://github.com/tukaani-project/xz/security/advisories/GHSA-x872-m794-cxhv"},{"name":"https://github.com/tukaani-project/xz/commit/c8c22869e780ff57c96b46939c3d79ff99395f87","tags":["x_refsource_MISC"],"url":"https://github.com/tukaani-project/xz/commit/c8c22869e780ff57c96b46939c3d79ff99395f87"},{"name":"https://github.com/tukaani-project/xz/releases/tag/v5.8.3","tags":["x_refsource_MISC"],"url":"https://github.com/tukaani-project/xz/releases/tag/v5.8.3"}],"source":{"advisory":"GHSA-x872-m794-cxhv","discovery":"UNKNOWN"},"title":"XZ Utils: Buffer overflow in lzma_index_append()"}},"cveMetadata":{"assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","assignerShortName":"GitHub_M","cveId":"CVE-2026-34743","datePublished":"2026-04-02T18:36:37.450Z","dateReserved":"2026-03-30T19:17:10.224Z","dateUpdated":"2026-04-03T12:59:06.096Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-04-02 19:21:33","lastModifiedDate":"2026-04-15 17:33:17","problem_types":["CWE-122","CWE-122 CWE-122: Heap-based Buffer Overflow"],"metrics":{"cvssMetricV40":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/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","baseScore":1.7,"baseSeverity":"LOW","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"LOW","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"UNREPORTED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}],"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","baseScore":5.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"LOW"},"exploitabilityScore":3.9,"impactScore":1.4}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:tukaani:xz:*:*:*:*:*:*:*:*","versionEndExcluding":"5.8.3","matchCriteriaId":"02E6038F-3DCB-4701-AC7E-1313F4F1FFB5"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"34743","Ordinal":"1","Title":"XZ Utils: Buffer overflow in lzma_index_append()","CVE":"CVE-2026-34743","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"34743","Ordinal":"1","NoteData":"XZ Utils provide a general-purpose data-compression library plus command-line tools. Prior to version 5.8.3, if lzma_index_decoder() was used to decode an Index that contained no Records, the resulting lzma_index was left in a state where where a subsequent lzma_index_append() would allocate too little memory, and a buffer overflow would occur. This issue has been patched in version 5.8.3.","Type":"Description","Title":"XZ Utils: Buffer overflow in lzma_index_append()"}]}}}