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CVE-2026-103635

Status: Undergoing AnalysisCritical (9.1)—
Severity9.1Critical · CVSS 3.1
Exploitation probability0.60 %higher than 48% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitNot knownno public code found

Out-of-bounds read in the compact Theta sketch deserialization of Apache DataSketches C++ (repo: datasketches-cpp).

compact_theta_sketch::deserialize() and wrapped_compact_theta_sketch::wrap() read header fields before checking that the input was long enough. For the compressed format, the size check could be defeated by a 32-bit overflow, and two header fields that control decoding were not validated; this also affected deserialization from a stream. A crafted or truncated sketch could cause a read past the end of the input. In the compressed case the over-read can be large, and the bytes read can become part of the deserialized sketch. This can cause a crash (denial of service) and could expose adjacent memory contents.

Read full descriptionShow less

This issue affects Apache DataSketches C++: from 3.1.0 before 5.3.0. Only applications that deserialize Theta sketches from untrusted sources are affected.

Users are recommended to upgrade to version 5.3.0, which fixes this issue.

CVSS

Base score
9.1
Version
3.1
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days
0.60 %
Percentile among all scored CVEs
48
Score date
10/20/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

Vector AV:N/PR:N/UI:N permite explotación remota sin autenticación; el texto indica lectura fuera de límites que puede causar caída (DoS) y exponer memoria adyacente.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

ATT&CK mitigations that cover these techniques

Filter Network TrafficVulnerability ScanningPrivileged Account ManagementNetwork SegmentationLimit Access to Resource Over NetworkApplication Isolation and Sandboxing

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Apache — DatasketchesAI

CWEs

References

Show 3 references

Raw JSON (NVD)

Show
{
  "id": "CVE-2026-103635",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-103635",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-10-16T15:27:43.270802Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 9.1,
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.2,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "security@apache.org",
      "affectedData": [
        {
          "vendor": "Apache Software Foundation",
          "product": "Apache DataSketches",
          "versions": [
            {
              "status": "affected",
              "version": "3.1.0",
              "versionType": "semver",
              "lessThanOrEqual": "5.2.0"
            }
          ],
          "packageURL": "pkg:github/apache/datasketches-cpp",
          "packageName": "apache/datasketches-cpp",
          "collectionURL": "https://github.com",
          "defaultStatus": "unaffected"
        }
      ]
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  ],
  "published": "2026-10-10T11:17:35.963",
  "references": [
    {
      "url": "https://github.com/apache/datasketches-cpp/releases/tag/5.3.0",
      "source": "security@apache.org"
    },
    {
      "url": "https://lists.apache.org/thread/15b86y9jstco39kzppjw7l5kvhjvwqvv",
      "source": "security@apache.org"
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    {
      "url": "http://www.openwall.com/lists/oss-security/2026/10/10/5",
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  "vulnStatus": "Undergoing Analysis",
  "weaknesses": [
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      "type": "Secondary",
      "source": "security@apache.org",
      "description": [
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          "value": "CWE-125"
        },
        {
          "lang": "en",
          "value": "CWE-190"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Out-of-bounds read in the compact Theta sketch deserialization of Apache DataSketches C++ (repo: datasketches-cpp).\n\ncompact_theta_sketch::deserialize() and wrapped_compact_theta_sketch::wrap() read header fields before checking that the input was long enough. For the compressed format, the size check could be defeated by a 32-bit overflow, and two header fields that control decoding were not validated; this also affected deserialization from a stream. A crafted or truncated sketch could cause a read past the end of the input. In the compressed case the over-read can be large, and the bytes read can become part of the deserialized sketch. This can cause a crash (denial of service) and could expose adjacent memory contents.\n\nThis issue affects Apache DataSketches C++: from 3.1.0 before 5.3.0. Only applications that deserialize Theta sketches from untrusted sources are affected.\n\nUsers are recommended to upgrade to version 5.3.0, which fixes this issue."
    }
  ],
  "lastModified": "2026-10-16T16:16:53.760",
  "sourceIdentifier": "security@apache.org"
}