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NVD / CVE Program· CNA VulnCheck

CVE-2026-71940: DrayTek VigorSwitch Multiple Models Buffer Overflow via acl_general_setup Edit ACE

Noroxi assessment

Priority: Monitor (action score 34/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.68% (FIRST EPSS); higher than 52.7% of all records.
  • Anyone who can reach it over the internet can trigger it. Administrator privileges are required. No user action is required. No special conditions are required; it is repeatable.
  • According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Multiple DrayTek VigorSwitch models contain a buffer overflow vulnerability in the acl_general_setup Edit ACE function. The vulnerability is caused by copying the name field into a fixed-size buffer without length validation. A remote attacker can trigger this vulnerability via crafted input, causing a denial of service or potentially executing arbitrary commands. Exploitation requires valid administrative credentials for the device's web management interface.

HighCVSS 8.6 · v4.0—No exploit No fix recorded
Published
Aug 24, 2026
Updated
Oct 12, 2026
EPSS
0.6% · 52th percentile

Report tools

JSON

Action score

34

Monitor

Low priority for now.

CVSS
34 / 40 · 8.6 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.6%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · VulnCheck
8.6
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-71940

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.

  • DrayTek Corporation VigorSwitch FX2120

    • before 3.9.10affected

  • DrayTek Corporation VigorSwitch G1280

    • before 2.9.10affected

  • DrayTek Corporation VigorSwitch G1282

    • before 2.9.10affected

  • DrayTek Corporation VigorSwitch G2100

    • before 2.9.10affected

  • DrayTek Corporation VigorSwitch G2121

    • before 2.9.10affected

  • DrayTek Corporation VigorSwitch G2280x

    • before 2.9.10affected

  • DrayTek Corporation VigorSwitch G2282x

    • before 2.10.6affected

  • DrayTek Corporation VigorSwitch G2540x

    • before 2.9.10affected

  • DrayTek Corporation VigorSwitch G2540xs

    • before 3.9.10affected

  • DrayTek Corporation VigorSwitch G2542x

    • before 3.10.6affected

  • DrayTek Corporation VigorSwitch P1280

    • before 2.9.10affected

  • DrayTek Corporation VigorSwitch P1281x

    • before 2.9.10affected

Same product

draytek corporation: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-71921DrayTek VigorSwitch Multiple Models Pre-Authentication OS Command Injection via setget.cgi
    38Monitor
  • CVE-2026-71943DrayTek VigorSwitch Multiple Models OS Command Injection via setDevNet
    35Monitor
  • CVE-2026-71933DrayTek VigorSwitch Multiple Models Missing Authorization in Syslog Functions
    35Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-71938Aug 24, 2026 · DrayTek VigorSwitch Multiple Models Buffer Overflow via switch_lan_gvrp
    34Monitor
  • ← EarlierCVE-2026-71939Aug 24, 2026 · DrayTek VigorSwitch Multiple Models Buffer Overflow via acl_general_setup Add ACE
    34Monitor
  • Later →CVE-2026-71941Aug 24, 2026 · DrayTek VigorSwitch Multiple Models Buffer Overflow via diag_logmail
    34Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-719360 days apartDrayTek VigorSwitch Multiple Models Buffer Overflow via sysreboot
    34Monitor
  • CVE-2026-719370 days apartDrayTek VigorSwitch Multiple Models Buffer Overflow via poe_schedule_profile
    34Monitor
  • CVE-2026-719380 days apartDrayTek VigorSwitch Multiple Models Buffer Overflow via switch_lan_gvrp
    34Monitor
  • CVE-2026-719390 days apartDrayTek VigorSwitch Multiple Models Buffer Overflow via acl_general_setup Add ACE
    34Monitor
  • CVE-2026-719410 days apartDrayTek VigorSwitch Multiple Models Buffer Overflow via diag_logmail
    34Monitor
  • CVE-2026-719420 days apartDrayTek VigorSwitch Multiple Models Buffer Overflow via mail_mailalert
    34Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • Administrator privileges are required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
High
User interaction
None
Scope
X

Weakness class (CWE)

CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Root cause

When data is copied, the source length is not compared with the size of the destination buffer. Excess data overwrites adjacent memory.

The bug in code

The whole CWE-120 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

c
char buf[256];memcpy(buf, pkt->data, pkt->len);

Fixed

c
char buf[256];if (pkt->len > sizeof(buf)) {  return -EINVAL;}memcpy(buf, pkt->data, pkt->len);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records