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Vulnerability record · CVE-2021-3304 · published 26 January 2021

CVE-2021-3304: Sagemcom f\@st 3686 firmware classic buffer overflow vulnerability

Sagemcom · F\@St 3686 Firmware

Sagemcom F@ST 3686 v2 3.495 devices have a buffer overflow via a long sessionKey to the goform/login URI.

9.8 CVSS 3.1 Critical EPSS 1.6% · top 25.0% CWE-120 · Classic buffer overflow
9.8CVSS 3.1 base score, v2 7.5
1.6%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

Sagemcom F@ST 3686 v2 3.495 devices have a buffer overflow via a long sessionKey to the goform/login URI.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://twitter.com/j0nh4t/status/1349649975479840769 ExploitThird Party Advisory
https://twitter.com/j0nh4t/status/1349649975479840769 ExploitThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2021-3304), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.