CVE-2026-3978Public exploitNetwork attack vector

Authenticated code execution via unchecked sprintf

Published Mar 12, 2026 · Updated Mar 12, 2026

Stack-based buffer overflow in D-Link DIR-513 1.10 allows remote authenticated users to execute code via a crafted setup request. The Boa formEasySetupWizard3 handler passes the user-controlled wan_connected value to sprintf without a length check, overflowing stack buffer v14. Low-privileged access to the web interface is required; successful exploitation can crash the router or execute code in its firmware context.

CVSS severity8.8
High
EPSS probability0.71%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in D-Link DIR-513 1.10 allows remote authenticated users to execute code via a crafted setup request. The Boa formEasySetupWizard3 handler passes the user-controlled wan_connected value to sprintf without a length check, overflowing stack buffer v14. Low-privileged access to the web interface is required; successful exploitation can crash the router or execute code in its firmware context.

The record

CVE
CVE-2026-3978
Published
Mar 12, 2026
Updated
Mar 12, 2026
Vendor
D-Link
Product
DIR-513
Classifications
CWE-119, CWE-121, T1190
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Mar 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 12, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

D-Link · DIR-513version=1.10

Published CVSS scores

7.4VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
8.8VulDBCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.0VulDBAV:N/AC:L/Au:S/C:C/I:C/A:C
8.8VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-121Stack-based Buffer Overflow
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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