Vulnerability-Lookup

GHSA-G42R-M263-958H

Vulnerability from github – Published: 2026-08-28 12:30 – Updated: 2026-08-28 12:30

Details

SiYuan versions before v3.8.1 contain a server-side request forgery vulnerability in the http_request and web_fetch agent tools that perform DNS resolution only at guard time without validating the connect-time resolution. Attackers can use DNS rebinding to answer the guard resolution with a public IP and the connect resolution with a private or metadata IP, bypassing the SSRF defense to access cloud instance metadata and internal services.

Severity

8.2 (High)


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

8.4 (High)


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

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-82234"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-28T12:16:33Z",
    "severity": "HIGH"
  },
  "details": "SiYuan versions before v3.8.1 contain a server-side request forgery vulnerability in the http_request and web_fetch agent tools that perform DNS resolution only at guard time without validating the connect-time resolution. Attackers can use DNS rebinding to answer the guard resolution with a public IP and the connect resolution with a private or metadata IP, bypassing the SSRF defense to access cloud instance metadata and internal services.",
  "id": "GHSA-g42r-m263-958h",
  "modified": "2026-08-28T12:30:26Z",
  "published": "2026-08-28T12:30:26Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-x8gv-g2g3-65fj"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-82234"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/siyuan-before-3.8.1-ssrf-via-dns-rebinding-toctou"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:L/VA:N/SC:H/SI:L/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-2026-82234 (GCVE-0-2026-82234)

Vulnerability from cvelistv5 – Published: 2026-08-28 10:49 – Updated: 2026-08-28 16:10

Title

SiYuan before v3.8.1 SSRF via DNS-Rebinding TOCTOU

Summary

Severity

8.4 (High)


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

8.2 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-28 16:09 UTC

CWE

CWE-918 - Server-Side Request Forgery (SSRF)

Assigner

VulnCheck mitre root Scorecard

References

2 references

URL	Tags
https://github.com/siyuan-note/siyuan/security/ad…	vendor-advisory
https://www.vulncheck.com/advisories/siyuan-befor…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
siyuan-note	siyuan	Affected: 0 , < 3.8.1 (semver) Unaffected: 3.8.1 (semver) cpe:2.3:a:b3log:siyuan::::::::

Date Public

2026-08-13 00:00

Credits

joysinleung

Show details on NVD website

JSON

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  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-82234",
                "options": [
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                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-28T16:09:56.105772Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-28T16:10:07.633Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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            },
            {
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              "versionType": "semver"
            }
          ]
        }
      ],
      "cpeApplicability": [
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            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
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      },
      "references": [
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          "name": "GitHub Security Advisory (GHSA-x8gv-g2g3-65fj)",
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        },
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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.

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GHSA-G42R-M263-958H

CVE-2026-82234 (GCVE-0-2026-82234)

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Sightings

Nomenclature

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