{"id":"CVE-2026-71272","aliases":["EUVD-2026-53357","GHSA-w8cc-xr9f-mrh7"],"status":"published","title":"Memos Webhook DNS Rebinding TOCTOU SSRF in safeDialContext()","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.","severity":{"version":"3.1","score":8.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00257,"percentile":0.17445,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-367"],"published":"2026-08-05T12:26:19Z","modified":"2026-10-28T02:30:35Z","products":[{"vendor":"usememos","product":"memos"}],"references":[{"url":"https://github.com/usememos/memos","tags":["third-party-advisory","advisory"]},{"url":"https://github.com/usememos/memos/blob/main/internal/webhook/webhook.go","tags":["third-party-advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-71272","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-w8cc-xr9f-mrh7"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/71xxx/CVE-2026-71272.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-71272","title":"Memos Webhook DNS Rebinding TOCTOU SSRF in safeDialContext()","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.","status":"published","published":"2026-08-05T12:26:19.395Z","modified":"2026-08-10T11:46:48.194Z","cvss":[{"version":"3.1","score":8.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-367"],"updated_at":"2026-11-02T14:19:49.559463Z"}],"euvd":[{"id":"EUVD-2026-53357","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.","status":"published","published":"2026-08-05T12:26:19Z","modified":"2026-08-10T11:46:48Z","cvss":[{"version":"3.1","score":8.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N","level":"high"}],"updated_at":"2026-11-02T18:02:05.732685Z"}],"ghsa":[{"id":"GHSA-w8cc-xr9f-mrh7","title":"Memos' webhook dispatch function safeDialContext() (internal/webhook/webhook.go) resolves the...","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.","status":"published","published":"2026-08-05T15:32:20Z","modified":"2026-08-05T15:32:23Z","cvss":[{"version":"3.1","score":8.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N","level":"high"}],"cwes":["CWE-367"],"updated_at":"2026-11-02T15:10:07.328501Z"}],"nvd":[{"id":"CVE-2026-71272","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.","status":"published","published":"2026-08-05T13:24:51.573Z","modified":"2026-10-24T15:10:00.19Z","cvss":[{"version":"3.1","score":8.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N","level":"high","assessor":"secondary"}],"cwes":["CWE-367"],"updated_at":"2026-11-02T14:12:35.031043Z"}],"osv":[{"id":"CVE-2026-71272","title":"Memos Webhook DNS Rebinding TOCTOU SSRF in safeDialContext()","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.","status":"published","published":"2026-08-05T12:26:19.395Z","modified":"2026-10-28T02:30:35.108859743Z","cvss":[{"version":"3.1","score":8.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N","level":"high"}],"cwes":["CWE-367"],"updated_at":"2026-11-02T15:45:15.164658Z"}]}}