CVE-2026-103513 — Apache DataSketches: datasketches-cpp: Out-of-bounds read and write in the CPC sketch deserialization allows memory corruption via a crafted sketch
Out-of-bounds read and write in the CPC sketch deserialization of Apache DataSketches C++ (repo: datasketches-cpp). A crafted serialized CPC sketch passed to cpc_sketch::deserialize(), from either a byte buffer or a stream, can cause the decompressor to read past the end of the compressed data, because the read position was only checked after decoding finished. In the hybrid flavor, it can also cause a write outside an internal heap buffer, because decoded row indices were not validated. Several other header fields and decoded values, including lg_k, were also not validated. This can corrupt heap memory, causing a crash and potentially enabling further exploitation. This issue affects Apache DataSketches C++: from 2.0.0-incubating before 5.3.0. Only applications that deserialize CPC sketches from untrusted sources are affected. Users are recommended to upgrade to version 5.3.0, which fixes this issue.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Apache Software Foundation Apache DataSketches).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Apache Software Foundation | Apache DataSketches | ≥ 2.0.0-incubating and ≤ 5.2.0 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.19%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · apache software foundation/apache datasketches
- Source status changed · → Undergoing Analysis
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
3 on the record
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-103636 Apache DataSketches: datasketches-cpp: Out-of-bounds read in VarOpt union deserialization allows denial of service via a truncated sketch 5d
- Unknown CVE-2026-103635 Apache DataSketches: datasketches-cpp: Out-of-bounds read in compact Theta sketch deserialization allows denial of service via a crafted sketch 5d
- Unknown CVE-2026-103501 Apache DataSketches: datasketches-cpp: HLL CouponList Deserialization Buffer Overflow allows memory corruption via a crafted sketch 5d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-103513 is "Apache DataSketches: datasketches-cpp: Out-of-bounds read and write in the CPC sketch deserialization allows memory corruption via a crafted sketch", rated Unknown. It affects Apache DataSketches (Apache Software Foundation); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.19% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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