CVE-2026-12413 (GCVE-0-2026-12413)

Vulnerability from cvelistv5 – Published: 2026-07-02 21:19 – Updated: 2026-07-07 17:02
VLAI
Title
IKEv2 Denial of Service via malformed fragmentation
Summary
An invalidly formatted IKEv2 fragment causes the Libreswan pluto daemon to crash and restart. Continued exploitation would cause a denial of service. The function reassemble_v2_incoming_fragments() would ignore unknown outer payloads but still store these in a fixed size array msg_digest.digest[PAYLIMIT]. An off-by-one error in the assertion PASSERT(logger, md->digest_roof < elemsof(md->digest)) causes the daemon to abort. No remote code execution is possible. Any configuration that allows IKEv2 connections that do not set fragmentation=no are vulnerable. IKEv1 is not affected.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-06 18:12 UTC
CWE
Assigner
References
Impacted products
Vendor Product Version
The Libreswan Project libreswan Affected: 4.6 , ≤ 5.3 (semver)
Unaffected: 5.3.1 (semver)
Create a notification for this product.
Credits
Hu Xinyao
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-12413",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-06T18:12:21.499364Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-07T17:02:12.976Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "libreswan",
          "vendor": "The Libreswan Project",
          "versions": [
            {
              "lessThanOrEqual": "5.3",
              "status": "affected",
              "version": "4.6",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.3.1",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Hu Xinyao"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "An invalidly formatted IKEv2 fragment causes the Libreswan pluto daemon to crash and restart. Continued exploitation would cause a denial of service. The function reassemble_v2_incoming_fragments() would ignore unknown outer payloads but still store these in a fixed size array msg_digest.digest[PAYLIMIT]. An off-by-one error in the assertion PASSERT(logger, md-\u003edigest_roof \u003c elemsof(md-\u003edigest)) causes the daemon to abort. No remote code execution is possible. Any configuration that allows IKEv2 connections that do not set fragmentation=no are vulnerable. IKEv1 is not affected."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        },
        {
          "other": {
            "content": {
              "description": "Vendor-assessed severity. The daemon automatically restarts after the crash, requiring continued exploitation for sustained denial of service.",
              "value": "MEDIUM"
            },
            "type": "vendorSeverity"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-193",
              "description": "Off-by-one Error",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-617",
              "description": "Reachable Assertion",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-02T21:19:22.177Z",
        "orgId": "d42dc95b-23f1-4e06-9076-20753a0fb0df",
        "shortName": "libreswan"
      },
      "references": [
        {
          "name": "Libreswan Security Advisory",
          "url": "https://libreswan.org/security/CVE-2026-12413/CVE-2026-12413.txt"
        },
        {
          "name": "Libreswan CVE-2026-12413 Patches",
          "url": "https://libreswan.org/security/CVE-2026-12413/"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to libreswan 5.3.1 or later. Patches for libreswan 4.15 and 5.3 are available at https://libreswan.org"
        }
      ],
      "timeline": [
        {
          "lang": "en",
          "time": "2026-06-16T00:00:00.000Z",
          "value": "Libreswan notified of the issue via security@libreswan.org"
        },
        {
          "lang": "en",
          "time": "2026-06-16T00:00:00.000Z",
          "value": "Advanced notice given to supported customers and distributions"
        },
        {
          "lang": "en",
          "time": "2026-06-24T00:00:00.000Z",
          "value": "Public announcement and release of libreswan 5.3.1"
        }
      ],
      "title": "IKEv2 Denial of Service via malformed fragmentation",
      "workarounds": [
        {
          "lang": "en",
          "value": "If fragmentation is not needed, fragmentation=no can be added to all IKEv2 configurations. If fragmentation is needed, no workaround is possible and the fix needs to be applied."
        }
      ],
      "x_generator": {
        "engine": "cvelib 1.8.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "d42dc95b-23f1-4e06-9076-20753a0fb0df",
    "assignerShortName": "libreswan",
    "cveId": "CVE-2026-12413",
    "datePublished": "2026-07-02T21:19:22.177Z",
    "dateReserved": "2026-06-16T15:52:12.674Z",
    "dateUpdated": "2026-07-07T17:02:12.976Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-12413",
      "date": "2026-10-01",
      "epss": "0.00598",
      "percentile": "0.46667"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "libreswan",
                "vendor": "The Libreswan Project",
                "versions": [
                  {
                    "lessThanOrEqual": "5.3",
                    "status": "affected",
                    "version": "4.6",
                    "versionType": "semver"
                  },
                  {
                    "status": "unaffected",
                    "version": "5.3.1",
                    "versionType": "semver"
                  }
                ]
              }
            ],
            "source": "d42dc95b-23f1-4e06-9076-20753a0fb0df"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:libreswan:libreswan:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "535F926A-021B-40BB-929F-618252622EAB",
                    "versionEndExcluding": "5.3.1",
                    "versionStartIncluding": "4.6",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "An invalidly formatted IKEv2 fragment causes the Libreswan pluto daemon to crash and restart. Continued exploitation would cause a denial of service. The function reassemble_v2_incoming_fragments() would ignore unknown outer payloads but still store these in a fixed size array msg_digest.digest[PAYLIMIT]. An off-by-one error in the assertion PASSERT(logger, md-\u003edigest_roof \u003c elemsof(md-\u003edigest)) causes the daemon to abort. No remote code execution is possible. Any configuration that allows IKEv2 connections that do not set fragmentation=no are vulnerable. IKEv1 is not affected."
          }
        ],
        "id": "CVE-2026-12413",
        "lastModified": "2026-07-08T18:52:42.920",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 7.5,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 3.6,
              "source": "d42dc95b-23f1-4e06-9076-20753a0fb0df",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-12413",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "yes"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-06T18:12:21.499364Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-07-02T22:16:42.517",
        "references": [
          {
            "source": "d42dc95b-23f1-4e06-9076-20753a0fb0df",
            "tags": [
              "Vendor Advisory"
            ],
            "url": "https://libreswan.org/security/CVE-2026-12413/"
          },
          {
            "source": "d42dc95b-23f1-4e06-9076-20753a0fb0df",
            "tags": [
              "Vendor Advisory",
              "Mitigation"
            ],
            "url": "https://libreswan.org/security/CVE-2026-12413/CVE-2026-12413.txt"
          }
        ],
        "sourceIdentifier": "d42dc95b-23f1-4e06-9076-20753a0fb0df",
        "vulnStatus": "Analyzed",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-193"
              },
              {
                "lang": "en",
                "value": "CWE-617"
              }
            ],
            "source": "d42dc95b-23f1-4e06-9076-20753a0fb0df",
            "type": "Secondary"
          }
        ]
      }
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "metrics": [
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-12413",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "yes"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-07-06T18:12:21.499364Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-07-06T18:12:22.546Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "defaultStatus": "unaffected",
              "product": "libreswan",
              "vendor": "The Libreswan Project",
              "versions": [
                {
                  "lessThanOrEqual": "5.3",
                  "status": "affected",
                  "version": "4.6",
                  "versionType": "semver"
                },
                {
                  "status": "unaffected",
                  "version": "5.3.1",
                  "versionType": "semver"
                }
              ]
            }
          ],
          "credits": [
            {
              "lang": "en",
              "type": "finder",
              "value": "Hu Xinyao"
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "An invalidly formatted IKEv2 fragment causes the Libreswan pluto daemon to crash and restart. Continued exploitation would cause a denial of service. The function reassemble_v2_incoming_fragments() would ignore unknown outer payloads but still store these in a fixed size array msg_digest.digest[PAYLIMIT]. An off-by-one error in the assertion PASSERT(logger, md-\u003edigest_roof \u003c elemsof(md-\u003edigest)) causes the daemon to abort. No remote code execution is possible. Any configuration that allows IKEv2 connections that do not set fragmentation=no are vulnerable. IKEv1 is not affected."
            }
          ],
          "metrics": [
            {
              "cvssV3_1": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 7.5,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                "version": "3.1"
              },
              "format": "CVSS",
              "scenarios": [
                {
                  "lang": "en",
                  "value": "GENERAL"
                }
              ]
            },
            {
              "other": {
                "content": {
                  "description": "Vendor-assessed severity. The daemon automatically restarts after the crash, requiring continued exploitation for sustained denial of service.",
                  "value": "MEDIUM"
                },
                "type": "vendorSeverity"
              }
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "cweId": "CWE-193",
                  "description": "Off-by-one Error",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            },
            {
              "descriptions": [
                {
                  "cweId": "CWE-617",
                  "description": "Reachable Assertion",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-07-02T21:19:22.177Z",
            "orgId": "d42dc95b-23f1-4e06-9076-20753a0fb0df",
            "shortName": "libreswan"
          },
          "references": [
            {
              "name": "Libreswan Security Advisory",
              "url": "https://libreswan.org/security/CVE-2026-12413/CVE-2026-12413.txt"
            },
            {
              "name": "Libreswan CVE-2026-12413 Patches",
              "url": "https://libreswan.org/security/CVE-2026-12413/"
            }
          ],
          "solutions": [
            {
              "lang": "en",
              "value": "Upgrade to libreswan 5.3.1 or later. Patches for libreswan 4.15 and 5.3 are available at https://libreswan.org"
            }
          ],
          "timeline": [
            {
              "lang": "en",
              "time": "2026-06-16T00:00:00.000Z",
              "value": "Libreswan notified of the issue via security@libreswan.org"
            },
            {
              "lang": "en",
              "time": "2026-06-16T00:00:00.000Z",
              "value": "Advanced notice given to supported customers and distributions"
            },
            {
              "lang": "en",
              "time": "2026-06-24T00:00:00.000Z",
              "value": "Public announcement and release of libreswan 5.3.1"
            }
          ],
          "title": "IKEv2 Denial of Service via malformed fragmentation",
          "workarounds": [
            {
              "lang": "en",
              "value": "If fragmentation is not needed, fragmentation=no can be added to all IKEv2 configurations. If fragmentation is needed, no workaround is possible and the fix needs to be applied."
            }
          ],
          "x_generator": {
            "engine": "cvelib 1.8.0"
          }
        }
      },
      "cveMetadata": {
        "assignerOrgId": "d42dc95b-23f1-4e06-9076-20753a0fb0df",
        "assignerShortName": "libreswan",
        "cveId": "CVE-2026-12413",
        "datePublished": "2026-07-02T21:19:22.177Z",
        "dateReserved": "2026-06-16T15:52:12.674Z",
        "dateUpdated": "2026-07-07T17:02:12.976Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.



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.