CVE-2026-119197 (GCVE-0-2026-119197)

Vulnerability from cvelistv5 – Published: 2026-10-29 19:48 – Updated: 2026-10-29 19:48
VLAI
Title
pyasn1: Quadratic-complexity denial of service in binary REAL decoding
Summary
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.5, binary REAL decoding builds a large mantissa one octet at a time by shifting a growing integer and slicing the remaining byte string. Attacker-controlled ASN.1 includes a binary-encoded REAL with a large mantissa and reaches BER, CER, or DER decode(), with or without a schema containing REAL. RealPayloadDecoder.valueDecoder repeatedly performs a left shift, OR, and suffix copy for every mantissa octet, making decode time quadratic in mantissa length. A comparatively small REAL value can hold a decoding worker on one CPU core for seconds or longer and cause availability loss. This issue is fixed in version 0.6.5.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
  • CWE-407 - Inefficient Algorithmic Complexity
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7978 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
pyasn1 pyasn1 Affected: < 0.6.5
guessed Create a notification for this product.
Show details on NVD website
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        }
      ],
      "metrics": [
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            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
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      "problemTypes": [
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              "description": "CWE-407: Inefficient Algorithmic Complexity",
              "lang": "en",
              "type": "CWE"
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      "providerMetadata": {
        "dateUpdated": "2026-10-29T19:48:52.470Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
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          "name": "https://github.com/pyasn1/pyasn1/security/advisories/GHSA-mm57-4v3p-rchx",
          "tags": [
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          ],
          "url": "https://github.com/pyasn1/pyasn1/security/advisories/GHSA-mm57-4v3p-rchx"
        },
        {
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          "tags": [
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          "url": "https://github.com/pyasn1/pyasn1/pull/132"
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          "url": "https://github.com/pyasn1/pyasn1/releases/tag/v0.6.5"
        }
      ],
      "source": {
        "advisory": "GHSA-mm57-4v3p-rchx",
        "discovery": "UNKNOWN"
      },
      "title": "pyasn1: Quadratic-complexity denial of service in binary REAL decoding"
    }
  },
  "cveMetadata": {
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    "cveId": "CVE-2026-119197",
    "datePublished": "2026-10-29T19:48:52.470Z",
    "dateReserved": "2026-10-29T16:04:48.728Z",
    "dateUpdated": "2026-10-29T19:48:52.470Z",
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        "cveTags": [],
        "descriptions": [
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          }
        ],
        "id": "CVE-2026-119197",
        "lastModified": "2026-10-29T20:17:30.907",
        "metrics": {
          "cvssMetricV31": [
            {
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                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
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        "vulnStatus": "Received",
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            "type": "Primary"
          }
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    }
  }
}



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