CVE-2026-103635 — Apache DataSketches: datasketches-cpp: Out-of-bounds read in compact Theta sketch deserialization allows denial of service via a crafted sketch
Out-of-bounds read in the compact Theta sketch deserialization of Apache DataSketches C++ (repo: datasketches-cpp). compact_theta_sketch::deserialize() and wrapped_compact_thet…
Published: 2026-10-10 · CVSS: 9.1 · CVSS 3.1
Out-of-bounds read in the compact Theta sketch deserialization of Apache DataSketches C++ (repo: datasketches-cpp). compact_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. This issue affects Apache DataSketches C++: from 3.1.0 before 5.3.0. Only applications that deserialize Theta sketches from untrusted sources are affected. Users are recommended to upgrade to version 5.3.0, which fixes this issue.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7