Description
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.
Analysis
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Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| usememos | memos | unaffected |
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Remediation
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Tracking
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Advisories
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References
History
Wed, 05 Aug 2026 13:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | Memos Webhook DNS Rebinding TOCTOU SSRF in safeDialContext() | |
| Weaknesses | CWE-367 | |
| References |
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| Metrics |
cvssV3_1
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Subscriptions
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MITRE
Status: PUBLISHED
Assigner: TuranSec
Published:
Updated: 2026-08-05T12:52:35.512Z
Reserved: 2026-08-05T12:23:34.967Z
Link: CVE-2026-71272
Vulnrichment
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NVD
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Redhat
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OpenCVE Enrichment
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Weaknesses
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CWE-367
Time-of-check Time-of-use (TOCTOU) Race Condition