Vulnerability-Lookup

GHSA-59FC-PX6W-3G8V

Vulnerability from github – Published: 2026-10-14 00:31 – Updated: 2026-10-14 00:31

Details

Libreswan's pluto daemon has a use-after-free vulnerability when a client connecting using IKE over TCP closes the connection and another packet (retransmit or malicious) is received for the same tuple. IKE state is retained in memory after the client closes the connection, storing a pointer to iface_endpoint inside ike_sa.sa->st_iface_endpoint. Once this invalid pointer is used, the daemon crashes and restarts. This vulnerability can be triggered before the remote peer has authenticated itself. Continued exploitation can lead to a denial of service. Remote code execution could be possible. The IKE over TCP option is not enabled by default; only configurations that contain listen-tcp=yes are affected.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/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-2026-94453"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-13T22:19:30Z",
    "severity": "HIGH"
  },
  "details": "Libreswan\u0027s pluto daemon has a use-after-free vulnerability when a client connecting using IKE over TCP closes the connection and another packet (retransmit or malicious) is received for the same tuple. IKE state is retained in memory after the client closes the connection, storing a pointer to iface_endpoint inside ike_sa.sa-\u003est_iface_endpoint. Once this invalid pointer is used, the daemon crashes and restarts. This vulnerability can be triggered before the remote peer has authenticated itself. Continued exploitation can lead to a denial of service. Remote code execution could be possible. The IKE over TCP option is not enabled by default; only configurations that contain listen-tcp=yes are affected.",
  "id": "GHSA-59fc-px6w-3g8v",
  "modified": "2026-10-14T00:31:47Z",
  "published": "2026-10-14T00:31:47Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-94453"
    },
    {
      "type": "WEB",
      "url": "https://libreswan.org/security/CVE-2026-94453"
    },
    {
      "type": "WEB",
      "url": "https://libreswan.org/security/CVE-2026-94453/CVE-2026-94453.txt"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-94453 (GCVE-0-2026-94453)

Vulnerability from cvelistv5 – Published: 2026-10-13 21:27 – Updated: 2026-10-13 21:27

Title

IKEv2 Use-After-Free bug when using IKE-over-TCP

Summary

Severity

7.5 (High)


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

CWE

CWE-416 - Use After Free

Assigner

libreswan CNA under the mitre root

CNA scorecard – unranked: 8 records in the last 180 days, 10 needed details

References

2 references

URL	Tags
https://libreswan.org/security/CVE-2026-94453/CVE…	vendor-advisory
https://libreswan.org/security/CVE-2026-94453/	patch

Impacted products

1 product

Vendor	Product	Version
The Libreswan Project	libreswan	Affected: 4.0 , ≤ 5.3.2 (semver) Affected: 5.4 , ≤ 5.4 (semver) Unaffected: 5.3.3 (semver) Unaffected: 5.4.1 (semver)

Credits

Vlad Miu

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JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "collectionURL": "https://github.com/libreswan/libreswan",
          "defaultStatus": "unaffected",
          "packageName": "libreswan",
          "product": "libreswan",
          "repo": "https://github.com/libreswan/libreswan",
          "vendor": "The Libreswan Project",
          "versions": [
            {
              "lessThanOrEqual": "5.3.2",
              "status": "affected",
              "version": "4.0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.4",
              "status": "affected",
              "version": "5.4",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.3.3",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.4.1",
              "versionType": "semver"
            }
          ]
        }
      ],
      "configurations": [
        {
          "lang": "en",
          "value": "Only configurations with listen-tcp=yes are vulnerable. IKE over TCP is not enabled by default in libreswan."
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Vlad Miu"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Libreswan\u0027s pluto daemon has a use-after-free vulnerability when a client connecting using IKE over TCP closes the connection and another packet (retransmit or malicious) is received for the same tuple. IKE state is retained in memory after the client closes the connection, storing a pointer to iface_endpoint inside ike_sa.sa-\u003est_iface_endpoint. Once this invalid pointer is used, the daemon crashes and restarts. This vulnerability can be triggered before the remote peer has authenticated itself. Continued exploitation can lead to a denial of service. Remote code execution could be possible. The IKE over TCP option is not enabled by default; only configurations that contain listen-tcp=yes are affected."
        }
      ],
      "exploits": [
        {
          "lang": "en",
          "value": "No known exploitation in the wild. Exploitation requires IKE over TCP to be enabled (listen-tcp=yes). The vulnerability can be triggered remotely without authentication."
        }
      ],
      "impacts": [
        {
          "descriptions": [
            {
              "lang": "en",
              "value": "Denial of service and potential remote code execution via use-after-free when processing IKE-over-TCP connections"
            }
          ]
        }
      ],
      "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: High. Exploitation does not require authentication. IKE over TCP is not enabled by default but affects any configuration with listen-tcp=yes.",
              "value": "HIGH"
            },
            "type": "vendorSeverity"
          }
        }
      ],
      "problemTypes": [
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          "descriptions": [
            {
              "cweId": "CWE-416",
              "description": "CWE-416: Use After Free",
              "lang": "en",
              "type": "CWE"
            }
          ]
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      "providerMetadata": {
        "dateUpdated": "2026-10-13T21:27:43.376Z",
        "orgId": "d42dc95b-23f1-4e06-9076-20753a0fb0df",
        "shortName": "libreswan"
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      "references": [
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          "name": "Libreswan Security Advisory CVE-2026-94453",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://libreswan.org/security/CVE-2026-94453/CVE-2026-94453.txt"
        },
        {
          "name": "Libreswan CVE-2026-94453 Patches",
          "tags": [
            "patch"
          ],
          "url": "https://libreswan.org/security/CVE-2026-94453/"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to libreswan 5.3.3 or 5.4.1 or later. Patches are available at https://libreswan.org/security/CVE-2026-94453/"
        }
      ],
      "source": {
        "defects": [
          "CVE-2026-94453"
        ],
        "discovery": "EXTERNAL"
      },
      "taxonomyMappings": [
        {
          "taxonomyName": "ATT\u0026CK",
          "taxonomyRelations": [
            {
              "relationshipName": "maps to",
              "relationshipValue": "Application or System Exploitation (DoS)",
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      "timeline": [
        {
          "lang": "en",
          "time": "2026-09-16T00:00:00.000Z",
          "value": "Libreswan was notified of the issue via security@libreswan.org"
        },
        {
          "lang": "en",
          "time": "2026-09-24T00:00:00.000Z",
          "value": "Advanced notice given to supported customers and distributions"
        },
        {
          "lang": "en",
          "time": "2026-10-05T00:00:00.000Z",
          "value": "Public announcement and release of libreswan 5.3.3 and 5.4.1"
        }
      ],
      "title": "IKEv2 Use-After-Free bug when using IKE-over-TCP",
      "workarounds": [
        {
          "lang": "en",
          "value": "To temporarily disable IKE over TCP, set listen-tcp=no."
        }
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  "cveMetadata": {
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    "datePublished": "2026-10-13T21:27:43.376Z",
    "dateReserved": "2026-09-21T17:09:02.116Z",
    "dateUpdated": "2026-10-13T21:27:43.376Z",
    "state": "PUBLISHED"
  },
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  "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.

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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.
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