Vulnerability-Lookup

OESA-2026-1130 (CVE-2025-67725)

Vulnerability from osv_openeuler – Published: 2026-01-16 11:10 – Updated: 2026-08-06 11:10 – Source website

Summary

python-tornado security update

Details

Tornado is an open source version of the scalable, non-blocking web server and tools.

Security Fix(es):

Tornado is a Python web framework and asynchronous networking library. In versions 6.5.2 and below, a single maliciously crafted HTTP request can block the server's event loop for an extended period, caused by the HTTPHeaders.add method. The function accumulates values using string concatenation when the same header name is repeated, causing a Denial of Service (DoS). Due to Python string immutability, each concatenation copies the entire string, resulting in O(n²) time complexity. The severity can vary from high if max_header_size has been increased from its default, to low if it has its default value of 64KB. This issue is fixed in version 6.5.3.(CVE-2025-67725)

Severity

7.5 (High)


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

References

URL

Type

	https://www.openeuler.org/zh/security/security-bu…	ADVISORY
	https://nvd.nist.gov/vuln/detail/CVE-2025-67725	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "aarch64": [
          "python-tornado-debuginfo-6.5-2.oe2403sp1.aarch64.rpm",
          "python-tornado-debugsource-6.5-2.oe2403sp1.aarch64.rpm",
          "python-tornado-help-6.5-2.oe2403sp1.aarch64.rpm",
          "python3-tornado-6.5-2.oe2403sp1.aarch64.rpm"
        ],
        "src": [
          "python-tornado-6.5-2.oe2403sp1.src.rpm"
        ],
        "x86_64": [
          "python-tornado-debuginfo-6.5-2.oe2403sp1.x86_64.rpm",
          "python-tornado-debugsource-6.5-2.oe2403sp1.x86_64.rpm",
          "python-tornado-help-6.5-2.oe2403sp1.x86_64.rpm",
          "python3-tornado-6.5-2.oe2403sp1.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:24.03-LTS-SP1",
        "name": "python-tornado",
        "purl": "pkg:rpm/openEuler/python-tornado\u0026distro=openEuler-24.03-LTS-SP1"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.5-2.oe2403sp1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "aarch64": [
          "python-tornado-debuginfo-6.5-2.oe2403sp2.aarch64.rpm",
          "python-tornado-debugsource-6.5-2.oe2403sp2.aarch64.rpm",
          "python-tornado-help-6.5-2.oe2403sp2.aarch64.rpm",
          "python3-tornado-6.5-2.oe2403sp2.aarch64.rpm"
        ],
        "src": [
          "python-tornado-6.5-2.oe2403sp2.src.rpm"
        ],
        "x86_64": [
          "python-tornado-debuginfo-6.5-2.oe2403sp2.x86_64.rpm",
          "python-tornado-debugsource-6.5-2.oe2403sp2.x86_64.rpm",
          "python-tornado-help-6.5-2.oe2403sp2.x86_64.rpm",
          "python3-tornado-6.5-2.oe2403sp2.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:24.03-LTS-SP2",
        "name": "python-tornado",
        "purl": "pkg:rpm/openEuler/python-tornado\u0026distro=openEuler-24.03-LTS-SP2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.5-2.oe2403sp2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "aarch64": [
          "python-tornado-debuginfo-6.5-2.oe2403sp3.aarch64.rpm",
          "python-tornado-debugsource-6.5-2.oe2403sp3.aarch64.rpm",
          "python-tornado-help-6.5-2.oe2403sp3.aarch64.rpm",
          "python3-tornado-6.5-2.oe2403sp3.aarch64.rpm"
        ],
        "src": [
          "python-tornado-6.5-2.oe2403sp3.src.rpm"
        ],
        "x86_64": [
          "python-tornado-debuginfo-6.5-2.oe2403sp3.x86_64.rpm",
          "python-tornado-debugsource-6.5-2.oe2403sp3.x86_64.rpm",
          "python-tornado-help-6.5-2.oe2403sp3.x86_64.rpm",
          "python3-tornado-6.5-2.oe2403sp3.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:24.03-LTS-SP3",
        "name": "python-tornado",
        "purl": "pkg:rpm/openEuler/python-tornado\u0026distro=openEuler-24.03-LTS-SP3"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.5-2.oe2403sp3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "aarch64": [
          "python-tornado-debuginfo-5.0.2-11.oe2003sp4.aarch64.rpm",
          "python-tornado-debugsource-5.0.2-11.oe2003sp4.aarch64.rpm",
          "python2-tornado-5.0.2-11.oe2003sp4.aarch64.rpm",
          "python3-tornado-5.0.2-11.oe2003sp4.aarch64.rpm"
        ],
        "src": [
          "python-tornado-5.0.2-11.oe2003sp4.src.rpm"
        ],
        "x86_64": [
          "python-tornado-debuginfo-5.0.2-11.oe2003sp4.x86_64.rpm",
          "python-tornado-debugsource-5.0.2-11.oe2003sp4.x86_64.rpm",
          "python2-tornado-5.0.2-11.oe2003sp4.x86_64.rpm",
          "python3-tornado-5.0.2-11.oe2003sp4.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:20.03-LTS-SP4",
        "name": "python-tornado",
        "purl": "pkg:rpm/openEuler/python-tornado\u0026distro=openEuler-20.03-LTS-SP4"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.0.2-11.oe2003sp4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "aarch64": [
          "python-tornado-debuginfo-6.1-5.oe2203sp3.aarch64.rpm",
          "python-tornado-debugsource-6.1-5.oe2203sp3.aarch64.rpm",
          "python-tornado-help-6.1-5.oe2203sp3.aarch64.rpm",
          "python3-tornado-6.1-5.oe2203sp3.aarch64.rpm"
        ],
        "src": [
          "python-tornado-6.1-5.oe2203sp3.src.rpm"
        ],
        "x86_64": [
          "python-tornado-debuginfo-6.1-5.oe2203sp3.x86_64.rpm",
          "python-tornado-debugsource-6.1-5.oe2203sp3.x86_64.rpm",
          "python-tornado-help-6.1-5.oe2203sp3.x86_64.rpm",
          "python3-tornado-6.1-5.oe2203sp3.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:22.03-LTS-SP3",
        "name": "python-tornado",
        "purl": "pkg:rpm/openEuler/python-tornado\u0026distro=openEuler-22.03-LTS-SP3"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.1-5.oe2203sp3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "aarch64": [
          "python-tornado-debuginfo-6.1-5.oe2203sp4.aarch64.rpm",
          "python-tornado-debugsource-6.1-5.oe2203sp4.aarch64.rpm",
          "python-tornado-help-6.1-5.oe2203sp4.aarch64.rpm",
          "python3-tornado-6.1-5.oe2203sp4.aarch64.rpm"
        ],
        "src": [
          "python-tornado-6.1-5.oe2203sp4.src.rpm"
        ],
        "x86_64": [
          "python-tornado-debuginfo-6.1-5.oe2203sp4.x86_64.rpm",
          "python-tornado-debugsource-6.1-5.oe2203sp4.x86_64.rpm",
          "python-tornado-help-6.1-5.oe2203sp4.x86_64.rpm",
          "python3-tornado-6.1-5.oe2203sp4.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:22.03-LTS-SP4",
        "name": "python-tornado",
        "purl": "pkg:rpm/openEuler/python-tornado\u0026distro=openEuler-22.03-LTS-SP4"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.1-5.oe2203sp4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "aarch64": [
          "python-tornado-debuginfo-6.5-2.oe2403sp1.aarch64.rpm",
          "python-tornado-debugsource-6.5-2.oe2403sp1.aarch64.rpm",
          "python-tornado-help-6.5-2.oe2403sp1.aarch64.rpm",
          "python3-tornado-6.5-2.oe2403sp1.aarch64.rpm",
          "python-tornado-debuginfo-6.5-2.oe2403sp2.aarch64.rpm",
          "python-tornado-debugsource-6.5-2.oe2403sp2.aarch64.rpm",
          "python-tornado-help-6.5-2.oe2403sp2.aarch64.rpm",
          "python3-tornado-6.5-2.oe2403sp2.aarch64.rpm",
          "python-tornado-debuginfo-6.5-2.oe2403sp3.aarch64.rpm",
          "python-tornado-debugsource-6.5-2.oe2403sp3.aarch64.rpm",
          "python-tornado-help-6.5-2.oe2403sp3.aarch64.rpm",
          "python3-tornado-6.5-2.oe2403sp3.aarch64.rpm",
          "python-tornado-debuginfo-6.5-2.oe2403.aarch64.rpm",
          "python-tornado-debugsource-6.5-2.oe2403.aarch64.rpm",
          "python-tornado-help-6.5-2.oe2403.aarch64.rpm",
          "python3-tornado-6.5-2.oe2403.aarch64.rpm"
        ],
        "src": [
          "python-tornado-6.5-2.oe2403sp1.src.rpm",
          "python-tornado-6.5-2.oe2403sp2.src.rpm",
          "python-tornado-6.5-2.oe2403sp3.src.rpm",
          "python-tornado-6.5-2.oe2403.src.rpm"
        ],
        "x86_64": [
          "python-tornado-debuginfo-6.5-2.oe2403sp1.x86_64.rpm",
          "python-tornado-debugsource-6.5-2.oe2403sp1.x86_64.rpm",
          "python-tornado-help-6.5-2.oe2403sp1.x86_64.rpm",
          "python3-tornado-6.5-2.oe2403sp1.x86_64.rpm",
          "python-tornado-debuginfo-6.5-2.oe2403sp2.x86_64.rpm",
          "python-tornado-debugsource-6.5-2.oe2403sp2.x86_64.rpm",
          "python-tornado-help-6.5-2.oe2403sp2.x86_64.rpm",
          "python3-tornado-6.5-2.oe2403sp2.x86_64.rpm",
          "python-tornado-debuginfo-6.5-2.oe2403sp3.x86_64.rpm",
          "python-tornado-debugsource-6.5-2.oe2403sp3.x86_64.rpm",
          "python-tornado-help-6.5-2.oe2403sp3.x86_64.rpm",
          "python3-tornado-6.5-2.oe2403sp3.x86_64.rpm",
          "python-tornado-debuginfo-6.5-2.oe2403.x86_64.rpm",
          "python-tornado-debugsource-6.5-2.oe2403.x86_64.rpm",
          "python-tornado-help-6.5-2.oe2403.x86_64.rpm",
          "python3-tornado-6.5-2.oe2403.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:24.03-LTS",
        "name": "python-tornado",
        "purl": "pkg:rpm/openEuler/python-tornado\u0026distro=openEuler-24.03-LTS"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.5-2.oe2403"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "severity": "High"
  },
  "details": "Tornado is an open source version of the scalable, non-blocking web server and tools.\r\n\r\nSecurity Fix(es):\n\nTornado is a Python web framework and asynchronous networking library. In versions 6.5.2 and below, a single maliciously crafted HTTP request can block the server\u0026apos;s event loop for an extended period, caused by the HTTPHeaders.add method. The function accumulates values using string concatenation when the same header name is repeated, causing a Denial of Service (DoS).  Due to Python string immutability, each concatenation copies the entire string, resulting in O(n\u00b2) time complexity. The severity can vary from high if max_header_size has been increased from its default, to low if it has its default value of 64KB. This issue is fixed in version 6.5.3.(CVE-2025-67725)",
  "id": "OESA-2026-1130",
  "modified": "2026-08-06T11:10:10Z",
  "published": "2026-01-16T11:10:10Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-1130"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-67725"
    }
  ],
  "schema_version": "1.7.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "python-tornado security update",
  "upstream": [
    "CVE-2025-67725"
  ]
}

CVE-2025-67725 (GCVE-0-2025-67725)

Vulnerability from cvelistv5 – Published: 2025-12-12 05:49 – Updated: 2025-12-18 18:51

Title

Tornado is Vulnerable to Quadratic DoS via Repeated Header Coalescing

Summary

Severity

7.5 (High)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2025-12-18 18:50 UTC

CWE

CWE-400 - Uncontrolled Resource Consumption

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7994 records in the last 180 days details

References

3 references

URL	Tags
https://github.com/tornadoweb/tornado/security/ad…	x_refsource_CONFIRM
https://github.com/tornadoweb/tornado/commit/7714…	x_refsource_MISC
https://github.com/tornadoweb/tornado/releases/ta…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
tornadoweb	tornado	Affected: < 6.5.3

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2025-67725",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-12-18T18:50:52.619221Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-12-18T18:51:00.369Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "tornado",
          "vendor": "tornadoweb",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 6.5.3"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Tornado is a Python web framework and asynchronous networking library. In versions 6.5.2 and below, a single maliciously crafted HTTP request can block the server\u0027s event loop for an extended period, caused by the HTTPHeaders.add method. The function accumulates values using string concatenation when the same header name is repeated, causing a Denial of Service (DoS).  Due to Python string immutability, each concatenation copies the entire string, resulting in O(n\u00b2) time complexity. The severity can vary from high if max_header_size has been increased from its default, to low if it has its default value of 64KB. This issue is fixed in version 6.5.3."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-400",
              "description": "CWE-400: Uncontrolled Resource Consumption",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-12-12T05:49:41.523Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/tornadoweb/tornado/security/advisories/GHSA-c98p-7wgm-6p64",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/tornadoweb/tornado/security/advisories/GHSA-c98p-7wgm-6p64"
        },
        {
          "name": "https://github.com/tornadoweb/tornado/commit/771472cfdaeebc0d89a9cc46e249f8891a6b29cd",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/tornadoweb/tornado/commit/771472cfdaeebc0d89a9cc46e249f8891a6b29cd"
        },
        {
          "name": "https://github.com/tornadoweb/tornado/releases/tag/v6.5.3",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/tornadoweb/tornado/releases/tag/v6.5.3"
        }
      ],
      "source": {
        "advisory": "GHSA-c98p-7wgm-6p64",
        "discovery": "UNKNOWN"
      },
      "title": "Tornado is Vulnerable to Quadratic DoS via Repeated Header Coalescing"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2025-67725",
    "datePublished": "2025-12-12T05:49:41.523Z",
    "dateReserved": "2025-12-10T19:25:20.819Z",
    "dateUpdated": "2025-12-18T18:51:00.369Z",
    "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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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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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