{"id":"CVE-2026-103635","published":"2026-10-10T11:17:35.963","lastModified":"2026-10-16T16:16:53.760","description":"Out-of-bounds read in the compact Theta sketch deserialization of Apache DataSketches C++ (repo: datasketches-cpp).\n\ncompact_theta_sketch::deserialize() and wrapped_compact_theta_sketch::wrap() read header fields before checking that the input was long enough. For the compressed format, the size check could be defeated by a 32-bit overflow, and two header fields that control decoding were not validated; this also affected deserialization from a stream. A crafted or truncated sketch could cause a read past the end of the input. In the compressed case the over-read can be large, and the bytes read can become part of the deserialized sketch. This can cause a crash (denial of service) and could expose adjacent memory contents.\n\nThis issue affects Apache DataSketches C++: from 3.1.0 before 5.3.0. Only applications that deserialize Theta sketches from untrusted sources are affected.\n\nUsers are recommended to upgrade to version 5.3.0, which fixes this issue.","cvssScore":9.1,"cvssSeverity":"CRITICAL","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","cwes":["CWE-125","CWE-190"],"vendors":[],"products":[],"references":[{"url":"https://github.com/apache/datasketches-cpp/releases/tag/5.3.0","tags":[]},{"url":"https://lists.apache.org/thread/15b86y9jstco39kzppjw7l5kvhjvwqvv","tags":[]},{"url":"http://www.openwall.com/lists/oss-security/2026/10/10/5","tags":[]}],"exploitRefs":[{"url":"https://github.com/apache/datasketches-cpp/releases/tag/5.3.0","tags":[]}],"hasPoc":true,"ai":{"summary":"An out-of-bounds read vulnerability in Apache DataSketches C++ allows attackers to read memory beyond the intended sketch boundaries during deserialization, potentially leading to crashes or information disclosure. This affects applications that deserialize Theta sketches from untrusted sources.","exploitability":"Exploitation is moderately difficult as it requires crafting a malicious sketch file that triggers a 32-bit overflow and over-read conditions, but can be achieved with knowledge of the data format and sufficient control over input data.","blast_radius":"The impact is significant for applications processing untrusted sketch data, potentially causing denial of service or exposing sensitive memory contents to attackers who can provide crafted sketches.","remediation":"Upgrade to version 5.3.0 which fixes this out-of-bounds read vulnerability in compact_theta_sketch::deserialize() and wrapped_compact_theta_sketch::wrap().","detection":"No reliable host or network indicator is derivable from the published description.","tags":["memory-corruption","deserialization","denial-of-service","cve-2026","data-sketches","cpp"],"model":"garnet-coder","analyzedAt":"2026-10-17T08:48:14.829Z"}}