CVE-2026-103513 Apache Software Foundation CVE debrief

Who should care

Defenders and developers using Apache DataSketches C++ versions from 2.0.0-incubating before 5.3.0, especially those deserializing CPC sketches from untrusted sources, should assess exposure and upgrade to version 5.3.0.

Why it matters

CVE-2026-103513 is an out-of-bounds read and write vulnerability in Apache DataSketches C++'s CPC sketch deserialization. Defenders and developers using affected versions should assess exposure, verify deserialization processes, and upgrade to version 5.3.0 to prevent potential crashes and exploitation.

• Potential crash and memory corruption
• Possible exploitation after initial crash
• Need to verify deserialization processes and inputs
• Upgrade to version 5.3.0 to fix the issue

Technical summary

A crafted serialized CPC sketch passed to cpc_sketch::deserialize() can cause the decompressor to read past the end of the compressed data and write outside an internal heap buffer. This can corrupt heap memory, causing a crash and potentially enabling further exploitation. The issue affects Apache DataSketches C++ from 2.0.0-incubating before 5.3.0. Only applications that deserialize CPC sketches from untrusted sources are impacted. The vulnerability can cause heap memory corruption, leading to a crash and potential exploitation.

Defensive priority

Upgrade to version 5.3.0, assess exposure, and verify deserialization processes.

Recommended defensive actions

• Upgrade to Apache DataSketches C++ version 5.3.0
• Assess exposure to untrusted CPC sketch deserialization
• Verify deserialization processes and inputs
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability. Apache DataSketches C++ versions from 2.0.0-incubating before 5.3.0 are affected. Only applications that deserialize CPC sketches from untrusted sources are impacted.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.