CVE-2026-27650: OS Command Injection vulnerability exists in BUFFALO Wi-Fi router products

Q: How do I fix CVE-2026-27650?

wcr-1166dhpl firmware: upgrade to 1.01; wsr3600be4-kh firmware: upgrade to 6.02; wsr3600be4p firmware: upgrade to 5.02. Exact commands for each OS are on this page.

Q: Is CVE-2026-27650 being exploited?

CVE-2026-27650 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-2026-27650 affect?

CVE-2026-27650 affects wcr-1166dhpl firmware, wsr3600be4-kh firmware, wsr3600be4p firmware. Severity is critical (CVSS 9.8). OS Command Injection vulnerability exists in BUFFALO Wi-Fi router products. If this vulnerability is exploited, an arbitrary OS command may be executed on the products.

Q: How urgent is CVE-2026-27650?

Priority 54/100. Critical severity; Remotely exploitable, no login, no user action

This month

CRITICAL 9.8REMOTEUPGRADEUPGRADEUPGRADE

CVE-2026-27650 is a critical-severity flaw (CVSS 9.8) affecting wcr-1166dhpl firmware, wsr3600be4-kh firmware, wsr3600be4p firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

OS Command Injection vulnerability exists in BUFFALO Wi-Fi router products. If this vulnerability is exploited, an arbitrary OS command may be executed on the products.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.9% (top 39%)
CISA exploited list	No
Weakness	CWE-78
Published	2026-03-27
Last modified	2026-10-26

Publisher (CNA): JPCERT/CC · Vendor: buffalo

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-27 06:16 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

buffalo wcr-1166dhpl firmware UPGRADE

Affected: < 1.01

Fixed in: 1.01

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.

buffalo wsr3600be4-kh firmware UPGRADE

Affected: < 6.02

Fixed in: 6.02

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.

buffalo wsr3600be4p firmware UPGRADE

Affected: < 5.02

Fixed in: 5.02

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.

buffalo wxr-1750dhp firmware UPGRADE

Affected: < 2.63

Fixed in: 2.63

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.

buffalo wxr-1750dhp2 firmware UPGRADE

Affected: < 2.63

Fixed in: 2.63

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.

buffalo wxr18000be10p firmware UPGRADE

Affected: < 5.03

Fixed in: 5.03

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-2026-27650?

wcr-1166dhpl firmware: upgrade to 1.01; wsr3600be4-kh firmware: upgrade to 6.02; wsr3600be4p firmware: upgrade to 5.02. Exact commands for each OS are on this page.

Is CVE-2026-27650 being exploited?

CVE-2026-27650 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-2026-27650 affect?

CVE-2026-27650 affects wcr-1166dhpl firmware, wsr3600be4-kh firmware, wsr3600be4p firmware. Severity is critical (CVSS 9.8). OS Command Injection vulnerability exists in BUFFALO Wi-Fi router products. If this vulnerability is exploited, an arbitrary OS command may be executed on the products.

How urgent is CVE-2026-27650?

Priority 54/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

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References

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