Vulnerability-Lookup

PYSEC-2026-3961

Vulnerability from pysec - Published: 2026-08-27 17:21 - Updated: 2026-09-10 12:38

Details

openssl_encrypt versions before 1.4.9 fail to properly validate key derivation function costs in crafted files, allowing attackers to trigger unbounded memory and CPU exhaustion during pre-authentication processing. Attackers can supply malicious files with excessive KDF parameters to exhaust system resources and crash or wedge the process before password verification occurs.

Severity

8.7 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Impacted products

Name	purl
openssl-encrypt	pkg:pypi/openssl-encrypt

Aliases

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {},
      "package": {
        "ecosystem": "PyPI",
        "name": "openssl-encrypt",
        "purl": "pkg:pypi/openssl-encrypt"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.4.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.2.2",
        "0.2.3",
        "0.2.4",
        "0.2.5",
        "0.2.6",
        "0.3.0",
        "0.3.1",
        "0.3.2",
        "0.3.3",
        "0.4.0",
        "0.4.1",
        "0.4.2",
        "0.4.3",
        "0.4.4",
        "0.5.0",
        "0.5.1",
        "0.5.3",
        "0.6.0rc1",
        "0.7.0rc2",
        "0.7.1",
        "0.7.2",
        "0.8.0",
        "0.8.1",
        "0.8.2",
        "0.9.2",
        "1.0.0",
        "1.0.1",
        "1.0.2",
        "1.0.3",
        "1.1.0",
        "1.2.0",
        "1.2.1",
        "1.3.0",
        "1.3.1",
        "1.3.2",
        "1.3.3",
        "1.3.4",
        "1.3.5",
        "1.4.0",
        "1.4.0b3",
        "1.4.0b4",
        "1.4.0b5",
        "1.4.0b6",
        "1.4.0b7",
        "1.4.0b8",
        "1.4.1",
        "1.4.1rc2",
        "1.4.2",
        "1.4.4",
        "1.4.5",
        "1.4.6",
        "1.4.7",
        "1.4.8"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-81699",
    "GHSA-phmr-p567-q5g6"
  ],
  "details": "openssl_encrypt versions before 1.4.9 fail to properly validate key derivation function costs in crafted files, allowing attackers to trigger unbounded memory and CPU exhaustion during pre-authentication processing. Attackers can supply malicious files with excessive KDF parameters to exhaust system resources and crash or wedge the process before password verification occurs.",
  "id": "PYSEC-2026-3961",
  "modified": "2026-09-10T12:38:49.145673Z",
  "published": "2026-08-27T17:21:00.217Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-phmr-p567-q5g6"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.vulncheck.com/advisories/openssl-encrypt-before-1.4.9-denial-of-service-via-unbounded-kdf-cost"
    }
  ],
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-81699 (GCVE-0-2026-81699)

Vulnerability from cvelistv5 – Published: 2026-08-27 14:51 – Updated: 2026-08-28 15:59

Title

openssl_encrypt before 1.4.9 Denial of Service via unbounded KDF cost

Summary

Severity

8.7 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-27 18:38 UTC

CWE

CWE-770 - Allocation of Resources Without Limits or Throttling

Assigner

VulnCheck mitre root

References

2 references

URL	Tags
https://github.com/jahlives/openssl_encrypt/secur…	vendor-advisory
https://www.vulncheck.com/advisories/openssl-encr…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
jahlives	openssl_encrypt	Affected: 0 , < 1.4.9 (semver) Unaffected: 1.4.9 (semver)

Date Public

2026-08-12 00:00

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-81699",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-27T18:38:48.311398Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-28T15:59:12.631Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:pypi/openssl-encrypt",
          "product": "openssl_encrypt",
          "vendor": "jahlives",
          "versions": [
            {
              "lessThan": "1.4.9",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "1.4.9",
              "versionType": "semver"
            }
          ]
        }
      ],
      "datePublic": "2026-08-12T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "openssl_encrypt versions before 1.4.9 fail to properly validate key derivation function costs in crafted files, allowing attackers to trigger unbounded memory and CPU exhaustion during pre-authentication processing. Attackers can supply malicious files with excessive KDF parameters to exhaust system resources and crash or wedge the process before password verification occurs."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS"
        },
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
            "version": "3.1"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
              "description": "Allocation of Resources Without Limits or Throttling",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-27T14:51:03.419Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "GitHub Security Advisory (GHSA-phmr-p567-q5g6)",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-phmr-p567-q5g6"
        },
        {
          "name": "VulnCheck Advisory: openssl_encrypt before 1.4.9 Denial of Service via unbounded KDF cost",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/openssl-encrypt-before-1.4.9-denial-of-service-via-unbounded-kdf-cost"
        }
      ],
      "title": "openssl_encrypt before 1.4.9 Denial of Service via unbounded KDF cost",
      "x_generator": {
        "engine": "vulncheck-endgame"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-81699",
    "datePublished": "2026-08-27T14:51:03.419Z",
    "dateReserved": "2026-08-27T11:12:29.817Z",
    "dateUpdated": "2026-08-28T15:59:12.631Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

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PYSEC-2026-3961

CVE-2026-81699 (GCVE-0-2026-81699)

Tags

Sightings

Nomenclature

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