Vulnerability-Lookup

GHSA-W8CC-XR9F-MRH7

Vulnerability from github – Published: 2026-08-05 15:32 – Updated: 2026-08-05 15:32

Details

Memos' webhook dispatch function safeDialContext() (internal/webhook/webhook.go) resolves the target hostname via net.DefaultResolver.LookupHost() and validates the resulting IPs against reserved ranges, but then dials net.JoinHostPort(host, port) using the original hostname rather than the already-validated IP address. Because net.Dialer.DialContext() performs its own independent DNS resolution, an attacker controlling DNS for the webhook's hostname (e.g. via a short TTL) can return a public, allowed IP during validation and a different, internal IP at dial time — a classic time-of-check/time-of-use DNS-rebinding bypass of the SSRF protection.

Severity

8.5 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-71272"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-367"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-05T13:24:51Z",
    "severity": "HIGH"
  },
  "details": "Memos\u0027 webhook dispatch function safeDialContext() (internal/webhook/webhook.go) resolves the target hostname via net.DefaultResolver.LookupHost() and validates the resulting IPs against reserved ranges, but then dials net.JoinHostPort(host, port) using the original hostname rather than the already-validated IP address. Because net.Dialer.DialContext() performs its own independent DNS resolution, an attacker controlling DNS for the webhook\u0027s hostname (e.g. via a short TTL) can return a public, allowed IP during validation and a different, internal IP at dial time \u2014 a classic time-of-check/time-of-use DNS-rebinding bypass of the SSRF protection.",
  "id": "GHSA-w8cc-xr9f-mrh7",
  "modified": "2026-08-05T15:32:20Z",
  "published": "2026-08-05T15:32:20Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-71272"
    },
    {
      "type": "WEB",
      "url": "https://github.com/usememos/memos"
    },
    {
      "type": "WEB",
      "url": "https://github.com/usememos/memos/blob/main/internal/webhook/webhook.go"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-71272 (GCVE-0-2026-71272)

Vulnerability from cvelistv5 – Published: 2026-08-05 12:26 – Updated: 2026-08-05 15:54

Title

Memos Webhook DNS Rebinding TOCTOU SSRF in safeDialContext()

Summary

Severity

8.5 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-367

Assigner

TuranSec

References

2 references

URL	Tags
https://github.com/usememos/memos
https://github.com/usememos/memos/blob/main/inter…

Impacted products

1 product

Vendor	Product	Version
usememos	memos	Affected: 0 , ≤ 0.29.1 (semver)

Credits

Alibek Baxtiyorov

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-71272",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-05T15:54:35.331224Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-05T15:54:41.075Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "memos",
          "programFiles": [
            "internal/webhook/webhook.go"
          ],
          "vendor": "usememos",
          "versions": [
            {
              "lessThanOrEqual": "0.29.1",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Alibek Baxtiyorov"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Memos\u0027 webhook dispatch function safeDialContext() (internal/webhook/webhook.go) resolves the target hostname via net.DefaultResolver.LookupHost() and validates the resulting IPs against reserved ranges, but then dials net.JoinHostPort(host, port) using the original hostname rather than the already-validated IP address. Because net.Dialer.DialContext() performs its own independent DNS resolution, an attacker controlling DNS for the webhook\u0027s hostname (e.g. via a short TTL) can return a public, allowed IP during validation and a different, internal IP at dial time \u2014 a classic time-of-check/time-of-use DNS-rebinding bypass of the SSRF protection."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-367",
              "description": "CWE-367",
              "lang": "en",
              "type": "CWE"
            }
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        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:52:35.512Z",
        "orgId": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c",
        "shortName": "TuranSec"
      },
      "references": [
        {
          "url": "https://github.com/usememos/memos"
        },
        {
          "url": "https://github.com/usememos/memos/blob/main/internal/webhook/webhook.go"
        }
      ],
      "title": "Memos Webhook DNS Rebinding TOCTOU SSRF in safeDialContext()"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c",
    "assignerShortName": "TuranSec",
    "cveId": "CVE-2026-71272",
    "datePublished": "2026-08-05T12:26:19.395Z",
    "dateReserved": "2026-08-05T12:23:34.967Z",
    "dateUpdated": "2026-08-05T15:54:41.075Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "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.

Detection rules are retrieved from Rulezet.

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.

Action not permitted

GHSA-W8CC-XR9F-MRH7

CVE-2026-71272 (GCVE-0-2026-71272)

Tags

Sightings

Nomenclature