Vulnerability-Lookup

GHSA-WXC2-GRP8-F55H

Vulnerability from github – Published: 2026-07-20 15:32 – Updated: 2026-07-20 15:32

Details

ProFTPD before 1.3.9c and 1.3.10rc3 contains a heap-based buffer overflow vulnerability in the mod_sftp module that allows authenticated low-privilege attackers to achieve arbitrary code execution by sending crafted SFTP packet fragments exceeding the 16 KB reassembly buffer in the fxp.c component. Attackers can supply oversized fragments to trigger an incorrectly conditioned reallocation, corrupt pool freelist metadata, overwrite the root_fs BSS global pointer to reference a fake filesystem struct, and redirect pr_fsio_stat() to system() via a crafted RENAME request.

Severity

8.8 (High)


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

8.7 (High)


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

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-63090"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-122"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-20T15:16:45Z",
    "severity": "HIGH"
  },
  "details": "ProFTPD before 1.3.9c and 1.3.10rc3 contains a heap-based buffer overflow vulnerability in the mod_sftp module that allows authenticated low-privilege attackers to achieve arbitrary code execution by sending crafted SFTP packet fragments exceeding the 16 KB reassembly buffer in the fxp.c component. Attackers can supply oversized fragments to trigger an incorrectly conditioned reallocation, corrupt pool freelist metadata, overwrite the root_fs BSS global pointer to reference a fake filesystem struct, and redirect pr_fsio_stat() to system() via a crafted RENAME request.",
  "id": "GHSA-wxc2-grp8-f55h",
  "modified": "2026-07-20T15:32:09Z",
  "published": "2026-07-20T15:32:09Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63090"
    },
    {
      "type": "WEB",
      "url": "https://github.com/proftpd/proftpd/issues/2190"
    },
    {
      "type": "WEB",
      "url": "https://github.com/proftpd/proftpd/commit/4ee8701bcf425f11b3b2116e634ff3e655d918b1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/proftpd/proftpd/blob/master/RELEASE_NOTES"
    },
    {
      "type": "WEB",
      "url": "https://github.com/proftpd/proftpd/releases/tag/v1.3.10rc3-3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/proftpd/proftpd/releases/tag/v1.3.9c"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/proftpd-mod-sftp-heap-buffer-overflow-via-sftp-packet-reassembly"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/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-2026-63090 (GCVE-0-2026-63090)

Vulnerability from cvelistv5 – Published: 2026-07-20 14:22 – Updated: 2026-07-28 01:49 X_Open Source

Title

ProFTPD mod_sftp Heap Buffer Overflow via SFTP Packet Reassembly

Summary

Severity

8.7 (High)


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

8.8 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-21 15:33 UTC

CWE

CWE-122 - Heap-based Buffer Overflow

Assigner

VulnCheck mitre root

References

6 references

URL	Tags
https://github.com/proftpd/proftpd/blob/master/RE…	release-notes
https://github.com/proftpd/proftpd/releases/tag/v…	patchrelease-notes
https://github.com/proftpd/proftpd/releases/tag/v1.3.9c	patchrelease-notes
https://github.com/proftpd/proftpd/issues/2190	issue-tracking
https://github.com/proftpd/proftpd/commit/4ee8701…	patch
https://www.vulncheck.com/advisories/proftpd-mod-…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
proftpd	proftpd	Affected: 0 , < 1.3.9c (custom) Affected: 1.3.10rc1 , < 1.3.10rc3 (custom) cpe:2.3:a:proftpd:proftpd:::::::: cpe:2.3:a:proftpd:proftpd::::::::

Date Public

2026-06-26 00:00

Credits

Fabian Wahle with Hap Security

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-63090",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-21T15:33:06.549976Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-21T15:35:45.854Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "affected",
          "product": "proftpd",
          "repo": "https://github.com/proftpd/proftpd",
          "vendor": "proftpd",
          "versions": [
            {
              "lessThan": "1.3.9c",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            },
            {
              "lessThan": "1.3.10rc3",
              "status": "affected",
              "version": "1.3.10rc1",
              "versionType": "custom"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:proftpd:proftpd:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "1.3.9c",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:proftpd:proftpd:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "1.3.10rc3",
                  "versionStartIncluding": "1.3.10rc1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Fabian Wahle with Hap Security"
        }
      ],
      "datePublic": "2026-06-26T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "ProFTPD before 1.3.9c and 1.3.10rc3 contains a heap-based buffer overflow vulnerability in the mod_sftp module that allows authenticated low-privilege attackers to achieve arbitrary code execution by sending crafted SFTP packet fragments exceeding the 16 KB reassembly buffer in the fxp.c component. Attackers can supply oversized fragments to trigger an incorrectly conditioned reallocation, corrupt pool freelist metadata, overwrite the root_fs BSS global pointer to reference a fake filesystem struct, and redirect pr_fsio_stat() to system() via a crafted RENAME request."
        }
      ],
      "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": "LOW",
            "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:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        },
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-122",
              "description": "Heap-based Buffer Overflow",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-28T01:49:57.243Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "Release Notes",
          "tags": [
            "release-notes"
          ],
          "url": "https://github.com/proftpd/proftpd/blob/master/RELEASE_NOTES"
        },
        {
          "name": "ProFTPD 1.3.10rc3-3 Release Notes",
          "tags": [
            "patch",
            "release-notes"
          ],
          "url": "https://github.com/proftpd/proftpd/releases/tag/v1.3.10rc3-3"
        },
        {
          "name": "ProFTPD 1.3.9c Release Notes",
          "tags": [
            "patch",
            "release-notes"
          ],
          "url": "https://github.com/proftpd/proftpd/releases/tag/v1.3.9c"
        },
        {
          "name": "Pull Request",
          "tags": [
            "issue-tracking"
          ],
          "url": "https://github.com/proftpd/proftpd/issues/2190"
        },
        {
          "name": "Patch Commit",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/proftpd/proftpd/commit/4ee8701bcf425f11b3b2116e634ff3e655d918b1"
        },
        {
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/proftpd-mod-sftp-heap-buffer-overflow-via-sftp-packet-reassembly"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "tags": [
        "x_open-source"
      ],
      "title": "ProFTPD mod_sftp Heap Buffer Overflow via SFTP Packet Reassembly",
      "x_generator": {
        "engine": "vulncheck"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-63090",
    "datePublished": "2026-07-20T14:22:03.712Z",
    "dateReserved": "2026-07-15T15:45:44.600Z",
    "dateUpdated": "2026-07-28T01:49:57.243Z",
    "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.

Action not permitted

GHSA-WXC2-GRP8-F55H

CVE-2026-63090 (GCVE-0-2026-63090)

Tags

Sightings

Nomenclature

Related by attack behaviour