{"id":"CVE-2026-103501","title":"Heap buffer overflow in the HLL sketch deserialization of Apache DataSketches C++ (repo: datasketches-cpp).\n\nWhen deserializing a sketch in LIST mode, from either a byte buffer or a stream, the coupon count was read from the input and us…","summary":"Heap buffer overflow in the HLL sketch deserialization of Apache DataSketches C++ (repo: datasketches-cpp).\n\nWhen deserializing a sketch in LIST mode, from either a byte buffer or a stream, the coupon count was read from the input and us…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-122","CWE-1284"],"vendor":"Apache Software Foundation","product":"apache/datasketches-cpp","affected":["apache/datasketches-cpp >= 1.0.0-incubating <= 5.2.0"],"published":"2026-10-10","updated":"2026-10-16","sourceUpdated":"2026-10-16T16:16:53.233","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-103501","references":[{"url":"https://github.com/apache/datasketches-cpp/releases/tag/5.3.0","label":"security@apache.org"},{"url":"https://lists.apache.org/thread/n2oc2j841dzsv4239jjp08of66bo79c5","label":"security@apache.org"},{"url":"http://www.openwall.com/lists/oss-security/2026/10/10/2","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd","cve.org"],"epss":0.00555,"epssPercentile":0.46128,"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T15:21:43.590609Z"},"ingestedAt":"2026-10-10T11:31:21.931Z","slug":"CVE-2026-103501","body":"## Overview\n\nHeap buffer overflow in the HLL sketch deserialization of Apache DataSketches C++ (repo: datasketches-cpp).\n\nWhen deserializing a sketch in LIST mode, from either a byte buffer or a stream, the coupon count was read from the input and used as the number of entries to copy into a fixed buffer of 8 entries, without checking it against the buffer's capacity. A crafted sketch could cause a write of up to 988 bytes past the end of this internal heap buffer. This can corrupt heap memory, causing a crash and potentially enabling further exploitation.\n\nThis issue affects Apache DataSketches C++: from 1.0.0-incubating before 5.3.0. Only applications that deserialize HLL sketches from untrusted sources are affected.\n\nUsers are recommended to upgrade to version 5.3.0, which fixes this issue.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":223095,"id":"CVE-2026-103501","ts":1792172198674,"field":"cvss","old":null,"new":"9.8"},{"seq":223094,"id":"CVE-2026-103501","ts":1792172198674,"field":"severity","old":"none","new":"critical"}]}