CVE-2023-39086: ASUS RT-AC66U B1 3.0.0.4.286_51665 was discovered to transmit sensitive information in cleartext.

Routine

HIGH 7.5REMOTEMITIGATE

CVE-2023-39086 is a high-severity flaw (CVSS 7.5) affecting rt-ac66u b1 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

ASUS RT-AC66U B1 3.0.0.4.286_51665 was discovered to transmit sensitive information in cleartext.

Why this priority

High severity
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 68%)
CISA exploited list	No
Weakness	CWE-319
Published	2023-08-08
Last modified	2026-07-09

Publisher (CNA): MITRE · Vendor: asus

Last updated 2026-07-09 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-08-08 20:15 UTCPublished CVE record published
2026-07-09 01:18 UTCUpdated Record last modified

asus rt-ac66u b1 firmware MITIGATE

Affected: 3.0.0.4.286_51665

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.0.0.4.286_51665

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-2023-39086?

rt-ac66u b1 firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-39086 being exploited?

CVE-2023-39086 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-2023-39086 affect?

CVE-2023-39086 affects rt-ac66u b1 firmware. Severity is high (CVSS 7.5). ASUS RT-AC66U B1 3.0.0.4.286_51665 was discovered to transmit sensitive information in cleartext.

How urgent is CVE-2023-39086?

Priority 39/100. High severity; Remotely exploitable, no login, no user action

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References

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