Vulnerability Description
Out-of-bounds read and write in the Count-Min sketch deserialization of Apache DataSketches C++ (repo: datasketches-cpp). count_min_sketch::deserialize() did not include the preamble in its input size check, so a truncated sketch could cause a read of up to 16 bytes past the end of the input. In addition, the table size was computed from the serialized number of buckets and number of hash functions in 32-bit arithmetic. A crafted sketch could make it wrap to zero, so that the sketch deserialized with an empty table, and later updates and estimate queries read and wrote outside the heap allocation. This can corrupt heap memory, causing a crash and potentially enabling further exploitation. This issue affects Apache DataSketches C++: from 4.1.0 before 5.3.0. Only applications that deserialize Count-Min sketches from untrusted sources are affected. Users are recommended to upgrade to version 5.3.0, which fixes this issue.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/apache/datasketches-cpp/releases/tag/5.3.0
- https://lists.apache.org/thread/rkx9oh06g5cjc6vmmpqloxwfz0gzz01h
- http://www.openwall.com/lists/oss-security/2026/10/10/4
FAQ
What is CVE-2026-103634?
CVE-2026-103634 is a vulnerability with a CVSS score of 5.3 (MEDIUM). Out-of-bounds read and write in the Count-Min sketch deserialization of Apache DataSketches C++ (repo: datasketches-cpp). count_min_sketch::deserialize() did not include the preamble in its input siz...
How severe is CVE-2026-103634?
CVE-2026-103634 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-103634?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.