Vulnerability-Lookup

GHSA-WWVV-QF38-WPF3

Vulnerability from github – Published: 2026-09-15 18:32 – Updated: 2026-09-15 18:32

Details

Tornado before 6.5.8 contains a memory amplification vulnerability in parse_multipart_form_data that splits multipart data before validating the max_parts limit. Attackers can send crafted multipart requests with many parts to create large transient lists, exhausting server memory and causing denial of service.

Severity

7.5 (High)


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

8.7 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-91990"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-770"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-15T16:17:58Z",
    "severity": "HIGH"
  },
  "details": "Tornado before 6.5.8 contains a memory amplification vulnerability in parse_multipart_form_data that splits multipart data before validating the max_parts limit. Attackers can send crafted multipart requests with many parts to create large transient lists, exhausting server memory and causing denial of service.",
  "id": "GHSA-wwvv-qf38-wpf3",
  "modified": "2026-09-15T18:32:31Z",
  "published": "2026-09-15T18:32:31Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/tornadoweb/tornado/security/advisories/GHSA-8423-8fgw-73vq"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-91990"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/tornado-before-6.5.8-memory-amplification-dos-via-multipart"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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-2026-91990 (GCVE-0-2026-91990)

Vulnerability from cvelistv5 – Published: 2026-09-15 15:18 – Updated: 2026-09-15 16:05

Title

Tornado before 6.5.8 Memory Amplification DoS via multipart

Summary

Severity

8.7 (High)


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

7.5 (High)


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

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-15 16:04 UTC

CWE

CWE-770 - Allocation of Resources Without Limits or Throttling

Assigner

VulnCheck mitre root

References

2 references

URL	Tags
https://github.com/tornadoweb/tornado/security/ad…	vendor-advisory
https://www.vulncheck.com/advisories/tornado-befo…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
tornadoweb	tornado	Affected: 0 , < 6.5.8 (semver) Unaffected: 6.5.8 (semver) cpe:2.3:a:tornadoweb:tornado::::::::

Date Public

2026-08-07 00:00

Show details on NVD website

JSON

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  "containers": {
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        "metrics": [
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            "other": {
              "content": {
                "id": "CVE-2026-91990",
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                  },
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                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-15T16:04:53.956684Z",
                "version": "2.0.3"
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        "providerMetadata": {
          "dateUpdated": "2026-09-15T16:05:11.528Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
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            "url": "https://github.com/tornadoweb/tornado/security/advisories/GHSA-8423-8fgw-73vq"
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        "title": "CISA ADP Vulnrichment"
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            "subConfidentialityImpact": "NONE",
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            "valueDensity": "NOT_DEFINED",
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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.

Detection rules are retrieved from Rulezet.

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.