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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

No known exploitation. EPSS puts it in the 9th percentile. No fix published yet.

CVSS —Not scoredEPSS percentile9th0.2% chance in 30 daysCISA KEVNot listedNo confirmed exploitation
No public exploit knownFixNone yetNo fix or workaround published

Published Updated Sources: CVE.org, NVD

NVD CVE.org

What to do

No fixed build or workaround is published yet. Limit exposure and watch for a patch.

  • Apache Software Foundation Apache DataSketchesAffected: ≥ 4.1.0, ≤ 5.2.0Upgrade to: after 5.2.0Stated by: CVE record

Versions as the sources state them. Full version matrix after sign-in

What it is

From the CVE record

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.

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS9th
CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

0.2% chance of exploitation activity in the next 30 days, which ranks it in the 9th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

5 events over 0 days, from the signal feeds we watch.

  1. Publishedweakness classified, att&ck mapped, record updated, record updated

Affected products

Technical detail

Weaknesses

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Sources

References in the record

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