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

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JSON

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{
  "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: 2026-07-21 15:35 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 (v2.0.3)

CWE

CWE-122 - Heap-based Buffer Overflow

Assigner

VulnCheck

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)

Date Public

2026-06-26 00:00

Credits

Fabian Wahle with Hap Security

Show details on NVD website

JSON

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  "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"
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
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      }
    ],
    "cna": {
      "affected": [
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          "repo": "https://github.com/proftpd/proftpd",
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      "credits": [
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          "type": "finder",
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      "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."
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      ],
      "metrics": [
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            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
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            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "exploitMaturity": "NOT_DEFINED",
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            "subConfidentialityImpact": "NONE",
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            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
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            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
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          "scenarios": [
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          "name": "Release Notes",
          "tags": [
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          "url": "https://github.com/proftpd/proftpd/blob/master/RELEASE_NOTES"
        },
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          "tags": [
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            "release-notes"
          ],
          "url": "https://github.com/proftpd/proftpd/releases/tag/v1.3.10rc3-3"
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        },
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    "datePublished": "2026-07-20T14:22:03.712Z",
    "dateReserved": "2026-07-15T15:45:44.600Z",
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    "state": "PUBLISHED"
  },
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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.

Action not permitted

GHSA-WXC2-GRP8-F55H

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

Tags

Sightings

Nomenclature