CVE-2026-123338

EUVD-2026-125274
Out-of-bounds Write vulnerability in Apache DataSketches C++. An
  application that deserializes a REQ sketch from an untrusted source
  can have heap memory corrupted by a crafted sketch, because the
  serialized compactor headers were not validated.

  This issue affects Apache DataSketches C++: from 3.0.0 through 5.3.0.

  Users are recommended to upgrade to version 5.3.1, which fixes the
  issue.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
UNKNOWN
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Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Common Weakness Enumeration
References
https://github.com/apache/datasketches-cpp/commit/9839ffd2ccc038d453e38b545750a5ed2d589dea
https://github.com/apache/datasketches-cpp/pull/568
https://github.com/apache/datasketches-cpp/releases/tag/5.3.1
https://lists.apache.org/thread/wjsso4wl0f0nczwh7gd74kc5wckn1635
http://www.openwall.com/lists/oss-security/2026/11/13/2