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Public proof of concept

CVE-2026-3040

A public proof of concept exists; no exploitation attested.

  • Published2026-02-23
  • WeaknessCWE-77 · CWE-78

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A vulnerability was identified in DrayTek Vigor 300B up to 1.5.1.6. This affects the function cgiGetFile of the file /cgi-bin/mainfunction.cgi/uploadlangs of the component Web Management Interface. The manipulation of the argument File leads to os command injection. The attack may be initiated remotely. The exploit is publicly available and might be used. The vendor confirms that "300B is EoL, and this is an authenticated vulnerability. We don't plan to fix it." This vulnerability only affects products that are no longer supported by the maintainer.

Timeline

dates in UTC
  1. 2026-02-2322:16CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-3040?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-3040?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Draytek vigor300b firmwareversion to verify
BranchAffectedFixed in
1.5≤ 1.5.1.6no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

No fix published by the sources we read yet. NVD record

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • CISA-ADPSSVC decisionpoc2026-02-25
  • OpenCVESSVC decisionpoc—
  • CNACVSS 4.02read 2026-10-23
  • CNACVSS 3.14.7read 2026-10-23
  • NVDCVSS 3.17.2read 2026-10-23
  • CNACVSS 2.05.8read 2026-10-23
  • CNAweakness (CWE)CWE-77, CWE-78read 2026-10-23
  • NVDweakness (CWE)CWE-78read 2026-10-23
  • FIRST EPSSEPSS score8.0 %2026-10-22

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
CVSS 4.0 vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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
Published
2026-02-23
Last Modified
2026-06-17
NVD status
Analyzed

Frequently asked questions

What is CVE-2026-3040?

A vulnerability was identified in DrayTek Vigor 300B up to 1.5.1.6. This affects the function cgiGetFile of the file /cgi-bin/mainfunction.cgi/uploadlangs of the component Web Management Interface. The manipulation of the argument File leads to os command injection. The attack may be initiated remotely. The exploit is publicly available and might be used. The vendor confirms that "300B is EoL, and this is an authenticated vulnerability. We don't plan to fix it." This vulnerability only affects products that are no longer supported by the maintainer.

Is CVE-2026-3040 actively exploited?

A proof-of-concept exploit exists for CVE-2026-3040, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2026-3040?

CVE-2026-3040 has a CVSS v3 base score of 7.2 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

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