Vulnerability-Lookup

UBUNTU-CVE-2026-16599 (CVE-2026-16599)

Vulnerability from osv_ubuntu – Published: 2026-08-25 15:16 – Updated: 2026-09-24 21:27 – Source website

Details

GNU wget is vulnerable to denial of service in its FTP OPIE/S-KEY authentication functionality. The server-supplied sequence number from the FTP challenge line is used as an iteration count for an MD5 key-derivation loop without any upper bound validation. A malicious FTP server or a network attacker positioned to intercept FTP traffic can send a crafted OPIE challenge with a sequence number near INT_MAX, causing wget to perform up to approximately 2.1 billion MD5 computations and suspend for some time. The --timeout option does not mitigate this because it applies only to network I/O, not CPU computation. This issue was fixed in commit e9697d98e7249b0f68a6be040a4f3dcc5bc101fa

Severity

5.1 (Medium)


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

N/A (UNKNOWN)

low

References

URL

Type

	https://ubuntu.com/security/CVE-2026-16599	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-16599	REPORT
	https://cert.pl/en/posts/2026/08/CVE-2026-16599/	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "wget",
            "binary_version": "1.15-1ubuntu1.14.04.5+esm4"
          }
        ],
        "priority_reason": "Only a performance issue in a command line tool"
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "wget",
        "purl": "pkg:deb/ubuntu/wget@1.15-1ubuntu1.14.04.5+esm4?arch=source\u0026distro=esm-infra-legacy/trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.14-2ubuntu1",
        "1.14-5ubuntu1",
        "1.15-1ubuntu1",
        "1.15-1ubuntu1.14.04.1",
        "1.15-1ubuntu1.14.04.2",
        "1.15-1ubuntu1.14.04.3",
        "1.15-1ubuntu1.14.04.4",
        "1.15-1ubuntu1.14.04.5",
        "1.15-1ubuntu1.14.04.5+esm2",
        "1.15-1ubuntu1.14.04.5+esm3",
        "1.15-1ubuntu1.14.04.5+esm4"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "wget",
            "binary_version": "1.17.1-1ubuntu1.5+esm5"
          }
        ],
        "priority_reason": "Only a performance issue in a command line tool"
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "wget",
        "purl": "pkg:deb/ubuntu/wget@1.17.1-1ubuntu1.5+esm5?arch=source\u0026distro=esm-infra-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.16.1-1ubuntu1",
        "1.17.1-1ubuntu1",
        "1.17.1-1ubuntu1.1",
        "1.17.1-1ubuntu1.2",
        "1.17.1-1ubuntu1.3",
        "1.17.1-1ubuntu1.4",
        "1.17.1-1ubuntu1.5",
        "1.17.1-1ubuntu1.5+esm1",
        "1.17.1-1ubuntu1.5+esm3",
        "1.17.1-1ubuntu1.5+esm4",
        "1.17.1-1ubuntu1.5+esm5"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "wget",
            "binary_version": "1.19.4-1ubuntu2.2+esm5"
          }
        ],
        "priority_reason": "Only a performance issue in a command line tool"
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "wget",
        "purl": "pkg:deb/ubuntu/wget@1.19.4-1ubuntu2.2+esm5?arch=source\u0026distro=esm-infra/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.19.1-3ubuntu1",
        "1.19.1-3ubuntu1.1",
        "1.19.2-1ubuntu1",
        "1.19.3-2ubuntu1",
        "1.19.4-1ubuntu2",
        "1.19.4-1ubuntu2.1",
        "1.19.4-1ubuntu2.2",
        "1.19.4-1ubuntu2.2+esm1",
        "1.19.4-1ubuntu2.2+esm3",
        "1.19.4-1ubuntu2.2+esm4",
        "1.19.4-1ubuntu2.2+esm5"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "wget",
            "binary_version": "1.20.3-1ubuntu2.1+esm4"
          }
        ],
        "priority_reason": "Only a performance issue in a command line tool"
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "wget",
        "purl": "pkg:deb/ubuntu/wget@1.20.3-1ubuntu2.1+esm4?arch=source\u0026distro=esm-infra/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.20.3-1ubuntu1",
        "1.20.3-1ubuntu2",
        "1.20.3-1ubuntu2.1",
        "1.20.3-1ubuntu2.1+esm2",
        "1.20.3-1ubuntu2.1+esm3",
        "1.20.3-1ubuntu2.1+esm4"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "wget",
            "binary_version": "1.21.2-2ubuntu1.5"
          }
        ],
        "priority_reason": "Only a performance issue in a command line tool"
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "wget",
        "purl": "pkg:deb/ubuntu/wget@1.21.2-2ubuntu1.5?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.21-1ubuntu3",
        "1.21-1ubuntu4",
        "1.21-1ubuntu5",
        "1.21.2-2ubuntu1",
        "1.21.2-2ubuntu1.1",
        "1.21.2-2ubuntu1.3",
        "1.21.2-2ubuntu1.4",
        "1.21.2-2ubuntu1.5"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "wget",
            "binary_version": "1.21.4-1ubuntu4.5"
          }
        ],
        "priority_reason": "Only a performance issue in a command line tool"
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "wget",
        "purl": "pkg:deb/ubuntu/wget@1.21.4-1ubuntu4.5?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.21.3-1ubuntu1",
        "1.21.4-1ubuntu1",
        "1.21.4-1ubuntu2",
        "1.21.4-1ubuntu3",
        "1.21.4-1ubuntu4",
        "1.21.4-1ubuntu4.1",
        "1.21.4-1ubuntu4.3",
        "1.21.4-1ubuntu4.4",
        "1.21.4-1ubuntu4.5"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "wget",
            "binary_version": "1.25.0-2ubuntu4.4"
          }
        ],
        "priority_reason": "Only a performance issue in a command line tool"
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "wget",
        "purl": "pkg:deb/ubuntu/wget@1.25.0-2ubuntu4.4?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.25.0-2ubuntu3",
        "1.25.0-2ubuntu4",
        "1.25.0-2ubuntu4.2",
        "1.25.0-2ubuntu4.3",
        "1.25.0-2ubuntu4.4"
      ]
    }
  ],
  "aliases": [],
  "details": "GNU wget is vulnerable to denial of service in its FTP OPIE/S-KEY authentication functionality. The server-supplied sequence number from the FTP challenge line is used as an iteration count for an MD5 key-derivation loop without any upper bound validation. A malicious FTP server or a network attacker positioned to intercept FTP traffic can send a crafted OPIE challenge with a sequence number near INT_MAX, causing wget to perform up to approximately 2.1 billion MD5 computations and suspend for some time. The --timeout option does not mitigate this because it applies only to network I/O, not CPU computation. This issue was fixed in commit e9697d98e7249b0f68a6be040a4f3dcc5bc101fa",
  "id": "UBUNTU-CVE-2026-16599",
  "modified": "2026-09-24T21:27:30Z",
  "published": "2026-08-25T15:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-16599"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-16599"
    },
    {
      "type": "REPORT",
      "url": "https://cert.pl/en/posts/2026/08/CVE-2026-16599/"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "low",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-16599"
  ]
}

CVE-2026-16599 (GCVE-0-2026-16599)

Vulnerability from cvelistv5 – Published: 2026-08-25 14:17 – Updated: 2026-08-25 14:51

Title

Denial of Service in GNU wget

Summary

Severity

5.1 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-25 14:38 UTC

CWE

CWE-606 - Unchecked input for loop condition

Assigner

CERT-PL ENISA root

References

3 references

URL	Tags
https://cert.pl/en/posts/2026/08/CVE-2026-16599	third-party-advisory
https://gitlab.com/gnuwget/wget	product
https://gitlab.com/gnuwget/wget/-/commit/e9697d98…	patch

Impacted products

1 product

Vendor	Product	Version
GNU	wget	Affected: 0 , ≤ 1.25.0 (semver)

Credits

Michał Majchrowicz (AFINE Team) Marcin Wyczechowski (AFINE Team)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-16599",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-25T14:38:32.531936Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-25T14:51:53.738Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "wget",
          "repo": "https://gitlab.com/gnuwget/wget/",
          "vendor": "GNU",
          "versions": [
            {
              "lessThanOrEqual": "1.25.0",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
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        }
      ],
      "credits": [
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          "lang": "en",
          "type": "finder",
          "value": "Micha\u0142 Majchrowicz (AFINE Team)"
        },
        {
          "lang": "en",
          "type": "finder",
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        }
      ],
      "descriptions": [
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              "base64": false,
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      "metrics": [
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          "cvssV4_0": {
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            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "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.

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

UBUNTU-CVE-2026-16599 (CVE-2026-16599)

CVE-2026-16599 (GCVE-0-2026-16599)

Tags

Sightings

Nomenclature

Related by attack behaviour