Vulnerability-Lookup

GHSA-VHC7-QGWJ-VX6V

Vulnerability from github – Published: 2026-07-01 15:35 – Updated: 2026-07-01 15:35

Details

FatFs prior to R0.16 that use GPT scanning with 'FF_LBA64 = 1' contains an issue where an unbounded loop count derived from GPT header field GPTH_PtNum, enabling extremely long or effectively infinite mount-time scans. This maps to CWE-835 (Loop with Unreachable Exit Condition). Estimated CVSS v3.1 vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (4.6, Medium). The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Partial.

Severity

4.6 (Medium)


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

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-6684"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-835"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-01T15:17:12Z",
    "severity": "MODERATE"
  },
  "details": "FatFs prior to R0.16 that use GPT scanning with \u0027FF_LBA64 = 1\u0027 contains an issue where an unbounded loop count derived from GPT header field GPTH_PtNum, enabling extremely long or effectively infinite mount-time scans. This maps to CWE-835 (Loop with Unreachable Exit Condition). Estimated CVSS v3.1 vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (4.6, Medium). The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Partial.",
  "id": "GHSA-vhc7-qgwj-vx6v",
  "modified": "2026-07-01T15:35:20Z",
  "published": "2026-07-01T15:35:20Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-6684"
    },
    {
      "type": "WEB",
      "url": "https://elm-chan.org/fsw/ff"
    },
    {
      "type": "WEB",
      "url": "https://github.com/runZeroInc/vulns-2026-fatfs-chance"
    },
    {
      "type": "WEB",
      "url": "https://www.runzero.com/advisories/fatfs-gpt-scan-loop-dos-cve-2026-6684"
    },
    {
      "type": "WEB",
      "url": "https://www.runzero.com/blog/fatfs-bugs"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-6684 (GCVE-0-2026-6684)

Vulnerability from cvelistv5 – Published: 2026-07-01 13:45 – Updated: 2026-07-01 15:25

Title

FatFs Infinite Loop in GPT Partition Scan

Summary

Severity

4.6 (Medium)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-01 15:25 UTC

CWE

CWE-835 - Loop with unreachable exit condition ('infinite loop')

Assigner

runZero icscert root

References

4 references

URL	Tags
https://www.runzero.com/blog/fatfs-bugs/	third-party-advisory
https://github.com/runZeroInc/vulns-2026-fatfs-chance	technical-description
https://elm-chan.org/fsw/ff/	product
https://www.runzero.com/advisories/fatfs-gpt-scan…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
ChaN	FatFs	Affected: 0 , < R0.16 (custom)

Date Public

2026-07-01 13:00

Credits

HD Moore of runZero, Inc. Tod Beardsley of runZero, Inc.

Show details on NVD website

JSON

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    "adp": [
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        "metrics": [
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            "other": {
              "content": {
                "id": "CVE-2026-6684",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-01T15:25:35.369745Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
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          "dateUpdated": "2026-07-01T15:25:53.071Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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            "tags": [
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          "value": "HD Moore of runZero, Inc."
        },
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          "lang": "en",
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        }
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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.