CVE-2021-26709

Name: CVE-2021-26709
Creator: NVD / NIST
Published: 2021-04-07T11:15:12.167+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 40.08%

Last modified Jun 17, 2026

CVE-2021-26709 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. D-Link DSL-320B-D1 devices through EU_1.25 are prone to multiple Stack-Based Buffer Overflows that allow unauthenticated remote attackers to take over a device via the login.xgi user and pass parameters. NOTE: This vulnerability only affects products that are no longer supported by the maintainer. EPSS estimates a 40.08% chance of exploitation in the next 30 days.

Description

D-Link DSL-320B-D1 devices through EU_1.25 are prone to multiple Stack-Based Buffer Overflows that allow unauthenticated remote attackers to take over a device via the login.xgi user and pass parameters. NOTE: This vulnerability only affects products that are no longer supported by the maintainer

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

40.08%

98.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-787

Affected Software

Vendor	Product	Versions
D-Link	Dsl-320b-D1	<= eu_1.25

References

http://packetstormsecurity.com/files/162133/D-Link-DSL-320B-D1-Pre-Authentication-Buffer-Overflow.htmlExploit, Third Party Advisory, VDB Entry
http://seclists.org/fulldisclosure/2021/Apr/15Mailing List, Third Party Advisory
https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10216Vendor Advisory
https://www.dlink.com/en/security-bulletinVendor Advisory
http://packetstormsecurity.com/files/162133/D-Link-DSL-320B-D1-Pre-Authentication-Buffer-Overflow.htmlExploit, Third Party Advisory, VDB Entry
http://seclists.org/fulldisclosure/2021/Apr/15Mailing List, Third Party Advisory
https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10216Vendor Advisory
https://www.dlink.com/en/security-bulletinVendor Advisory

Timeline

Published: Apr 7, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-26709?

How severe is CVE-2021-26709?

CVE-2021-26709 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 40.08% probability of exploitation in the next 30 days.

How do I fix CVE-2021-26709?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-26709?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST