Vulnerability-Lookup

GHSA-937C-856W-W843

Vulnerability from github – Published: 2026-09-11 03:30 – Updated: 2026-09-11 03:30

Details

libcharon in strongSwan 5.9.7 through 6.0.7 mishandles behavioral workflow in the IKEv2 state machine. Because CREATE_CHILD_SA requests are mishandled, there can be an authentication bypass.

Severity

5.6 (Medium)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-78135"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-841"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-11T03:16:23Z",
    "severity": "MODERATE"
  },
  "details": "libcharon in strongSwan 5.9.7 through 6.0.7 mishandles behavioral workflow in the IKEv2 state machine. Because\u00a0CREATE_CHILD_SA requests are mishandled, there can be an authentication bypass.",
  "id": "GHSA-937c-856w-w843",
  "modified": "2026-09-11T03:30:24Z",
  "published": "2026-09-11T03:30:24Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-78135"
    },
    {
      "type": "WEB",
      "url": "https://github.com/strongswan/strongswan/releases/tag/6.1.0"
    },
    {
      "type": "WEB",
      "url": "https://www.strongswan.org/blog/2026/09/07/strongswan-vulnerability-(cve-2026-78135).html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-78135 (GCVE-0-2026-78135)

Vulnerability from cvelistv5 – Published: 2026-09-11 02:07 – Updated: 2026-09-15 15:32

Summary

libcharon in strongSwan 5.9.7 through 6.0.7 mishandles behavioral workflow in the IKEv2 state machine. Because CREATE_CHILD_SA requests are mishandled, there can be an authentication bypass.

Severity

5.6 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-15 15:32 UTC

CWE

CWE-841 - Improper Enforcement of Behavioral Workflow

Assigner

mitre mitre root Scorecard

References

2 references

URL	Tags
https://github.com/strongswan/strongswan/releases…
https://www.strongswan.org/blog/2026/09/07/strong…

Impacted products

1 product

Vendor	Product	Version
strongSwan	strongSwan	Affected: 5.9.7 , < 6.1.0 (semver) cpe:2.3:a:strongswan:strongswan::::::::

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  "containers": {
    "adp": [
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        "metrics": [
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            "other": {
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                "id": "CVE-2026-78135",
                "options": [
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                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-15T15:32:40.015957Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
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          "dateUpdated": "2026-09-15T15:32:51.934Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
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          "vendor": "strongSwan",
          "versions": [
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              "status": "affected",
              "version": "5.9.7",
              "versionType": "semver"
            }
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      ],
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      ],
      "metrics": [
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          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
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            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
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          "url": "https://github.com/strongswan/strongswan/releases/tag/6.1.0"
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    "datePublished": "2026-09-11T02:07:28.763Z",
    "dateReserved": "2026-08-22T23:41:22.635Z",
    "dateUpdated": "2026-09-15T15:32:51.934Z",
    "state": "PUBLISHED"
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}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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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.
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GHSA-937C-856W-W843

CVE-2026-78135 (GCVE-0-2026-78135)

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