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
- Is it exploited?
Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.
- How likely is exploitation in the next 30 days?
- 0.4%
EPSS score, percentile 33.5 of all scored records. A probability estimated by FIRST, not a report of exploitation.
- How severe?
- 9.8 Critical
CVSS v3.1 base score, from CISA's enrichment of the record
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
- Which versions are affected?
Affected
- 2.0.0-incubating through 5.2.0
Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.
What to do
Advisories and patches
This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | 2.0.0-incubating through 5.2.0 |
Versions not listed are: unaffected.
Source: CVE List, as of . About the data.
About this vulnerability
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…
Summary: CVE record, as of .
- CISA has not added CVE-2026-103513 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
- The CVE record was published on 10 Oct 2026.
- The CVE record carries a CVSS v3.1 base score of 9.8 (Critical), taken from CISA's enrichment of the record.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.4% (percentile 33.5), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
- CISA's SSVC assessment in the CVE record: exploitation none, automatable yes, technical impact total.
Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.
Description
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.
Source: CVE List, as of . About the data.
Weakness
CWE-787, CWE-125
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| CVE record last updated |
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