CVE-2026-103634

Apache DataSketches: datasketches-cpp: Out-of-bounds read and write in Count-Min sketch deserialization allows memory corruption via a crafted sketch

Published Oct 22, 2026 CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Apache
Apache datasketches
Vendors & Products Apache
Apache datasketches
Type Values Removed Values Added
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.
Title Apache DataSketches: datasketches-cpp: Out-of-bounds read and write in Count-Min sketch deserialization allows memory corruption via a crafted sketch
Weaknesses CWE-190
CWE-787
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
apache
Published
Updated
Oct 26, 2026, 1:43 PM
Reserved
Sep 30, 2026, 11:36 PM
Status
Awaiting Analysis
Published
Oct 22, 2026, 7:16 AM
Modified
Oct 26, 2026, 2:16 PM