CVE-2026-103501: CWE-122 Heap-based buffer overflow in Apache Software Foundation Apache DataSketches
Description
A heap-based buffer overflow vulnerability exists in the Apache DataSketches C++ library during deserialization of HLL sketches in LIST mode. The flaw occurs because the coupon count from input is used to copy entries into a fixed-size buffer without bounds checking, allowing writes beyond the buffer's end. This can corrupt heap memory, potentially causing crashes or enabling further exploitation. The issue affects versions from 1.0.0-incubating up to 5.2.0. Upgrading to version 5.3.0 resolves the vulnerability. Only applications deserializing HLL sketches from untrusted sources are at risk.
Affected software
Apache Software Foundation
Apache DataSketches
pkg:github/apache/datasketches-cppRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-103501 describes a heap buffer overflow in the Apache DataSketches C++ library's HLL sketch deserialization process. When deserializing a sketch in LIST mode, the coupon count read from input is used as the number of entries to copy into a fixed buffer of 8 entries without verifying that the count does not exceed the buffer capacity. This allows an attacker to write up to 988 bytes beyond the allocated heap buffer, corrupting memory. This vulnerability affects versions >=1.0.0-incubating and <=5.2.0. The flaw can cause crashes and may enable further exploitation. The vendor fixed the issue in version 5.3.0.
Potential Impact
Heap memory corruption caused by the buffer overflow can lead to application crashes and may allow attackers to execute arbitrary code or cause denial of service if they can supply crafted HLL sketches for deserialization. Only applications that deserialize sketches from untrusted sources are vulnerable.
Mitigation Recommendations
Users should upgrade Apache DataSketches C++ to version 5.3.0 or later, which includes the fix for this vulnerability. Avoid deserializing HLL sketches from untrusted or unauthenticated sources until the upgrade is applied.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- apache
- Date Reserved
- 2026-09-30T17:29:03.761Z
- State
- PUBLISHED
Threat ID: 6aca148f2cdf04f65621aab9
Added to database: 10/10/2026, 10:33:51 UTC
Last enriched: 10/10/2026, 10:48:25 UTC
Last updated: 10/10/2026, 10:49:05 UTC
Views: 7
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