{"id":"CVE-2026-34743","summary":"XZ Utils: Buffer overflow in lzma_index_append()","details":"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.","aliases":["GHSA-x872-m794-cxhv"],"modified":"2026-07-23T08:25:11.790413Z","published":"2026-04-02T18:36:37.450Z","related":["SUSE-SU-2026:2051-1","SUSE-SU-2026:2052-1","SUSE-SU-2026:2118-1","SUSE-SU-2026:21729-1","SUSE-SU-2026:21740-1","SUSE-SU-2026:21835-1","SUSE-SU-2026:21848-1","openSUSE-SU-2026:10492-1","openSUSE-SU-2026:20813-1"],"database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-122"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34743.json"},"references":[{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/03/31/13"},{"type":"WEB","url":"https://github.com/tukaani-project/xz/releases/tag/v5.8.3"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2026/07/msg00034.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34743.json"},{"type":"ADVISORY","url":"https://github.com/tukaani-project/xz/security/advisories/GHSA-x872-m794-cxhv"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34743"},{"type":"FIX","url":"https://github.com/tukaani-project/xz/commit/c8c22869e780ff57c96b46939c3d79ff99395f87"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/tukaani-project/xz","events":[{"introduced":"0"},{"fixed":"4b73f2ec19a99ef465282fbce633e8deb33691b3"},{"fixed":"c8c22869e780ff57c96b46939c3d79ff99395f87"}],"database_specific":{"cpe":"cpe:2.3:a:tukaani:xz:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"fixed":"5.8.3"}],"source":["CPE_RANGE","REFERENCES"]}}],"versions":["v5.8.2","v5.8.1","v5.8.0","v5.7.2beta","v5.7.1alpha","v5.7.0alpha","v5.5.2beta","v5.5.1alpha","v5.5.0alpha","v5.4.0","v5.3.5beta","v5.3.4alpha","v5.3.3alpha","v5.3.2alpha","v5.3.1alpha","v5.2.1","v5.2.0","v5.1.4beta","v5.1.3alpha","v5.1.2alpha","v5.1.1alpha","v5.0.0","v5.1.0alpha","v4.999.9beta","v4.999.8beta","v4.999.7beta","v4.999.5alpha","v4.999.3alpha","v4.42.2alpha"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-34743.json","vanir_signatures_modified":"2026-07-23T08:25:11Z","vanir_signatures":[{"source":"https://github.com/tukaani-project/xz/commit/c8c22869e780ff57c96b46939c3d79ff99395f87","target":{"function":"lzma_index_append","file":"src/liblzma/common/index.c"},"deprecated":false,"digest":{"function_hash":"50025824752531838876270586168577736298","length":1799},"id":"CVE-2026-34743-8bf2b829","signature_type":"Function","signature_version":"v1"},{"signature_version":"v1","source":"https://github.com/tukaani-project/xz/commit/c8c22869e780ff57c96b46939c3d79ff99395f87","target":{"file":"src/liblzma/common/index.c"},"deprecated":false,"digest":{"line_hashes":["189021365865857008318232289039297103124","314911882038425734515188493524891833443","211617179559452375355043576420664790012","26911717901058952735636282764262730641","172566969959909635515254092570109171954","309215456910578642829530044367921726652"],"threshold":0.9},"id":"CVE-2026-34743-9c1f8a10","signature_type":"Line"},{"digest":{"function_hash":"328129197884697836206461655903934437677","length":152},"id":"CVE-2026-34743-aa610b77","signature_type":"Function","signature_version":"v1","source":"https://github.com/tukaani-project/xz/commit/c8c22869e780ff57c96b46939c3d79ff99395f87","target":{"file":"src/liblzma/common/index.c","function":"lzma_index_prealloc"},"deprecated":false}]}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"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"}]}