Vulnerability-Lookup

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

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

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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GHSA-W8CC-XR9F-MRH7

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

Details

Severity

8.5 (High)


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

Show details on source website

JSON

To clipboard

{
  "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"
    }
  ]
}

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

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

GHSA-W8CC-XR9F-MRH7

Tags

Sightings

Nomenclature