CVE-2026-3040: A vulnerability was identified in DrayTek Vigor 300B up to 1.5.1.6

Q: How do I fix CVE-2026-3040?

vigor300b firmware: upgrade to newer than 1.5.1.6. Exact commands for each OS are on this page.

Q: Is CVE-2026-3040 being exploited?

CVE-2026-3040 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-3040 affect?

CVE-2026-3040 affects vigor300b firmware. Severity is medium (CVSS 4.7). 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 lead

Q: How urgent is CVE-2026-3040?

Priority 45/100. EPSS top 4%: very likely to be exploited; Public exploit reference

This week

MEDIUM 4.7UPGRADE

CVE-2026-3040 is a medium-severity flaw (CVSS 4.7) affecting vigor300b firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

EPSS top 4%: very likely to be exploited
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	4.7 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	High
User interaction	None
EPSS exploit chance	10.1% (top 4%)
CISA exploited list	No
Weakness	CWE-77, CWE-78
Published	2026-02-23
Last modified	2026-06-17

Publisher (CNA): VulDB · Vendor: draytek

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-02-23 22:16 UTCPublished CVE record published
2026-06-17 10:42 UTCUpdated Record last modified

draytek vigor300b firmware UPGRADE

Affected: <= 1.5.1.6

Fixed in: newer than 1.5.1.6

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-3040?

vigor300b firmware: upgrade to newer than 1.5.1.6. Exact commands for each OS are on this page.

Is CVE-2026-3040 being exploited?

CVE-2026-3040 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-3040 affect?

CVE-2026-3040 affects vigor300b firmware. Severity is medium (CVSS 4.7). 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 lead

How urgent is CVE-2026-3040?

Priority 45/100. EPSS top 4%: very likely to be exploited; Public exploit reference

Related CVEs

CVE-2024-43027 HIGH 8.0 UPGRADE UPGRADE DrayTek Vigor 3900 before v1.5.1.5_Beta, DrayTek Vigor 2960 before v1.5.1.5_Beta and DrayTek Vigor 300B before
CVE-2024-12987 HIGH 7.3 EXPLOITED MITIGATE MITIGATE DrayTek Vigor Routers OS Command Injection Vulnerability
CVE-2024-12986 HIGH 7.3 UPGRADE UPGRADE A vulnerability, which was classified as critical, has been found in DrayTek Vigor2960 and Vigor300B 1.5.1.3/1

References

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