CVE-2018-8826: ASUS RT-AC51U, RT-AC58U, RT-AC66U, RT-AC1750, RT-ACRH13, and RT-N12 D1 routers with firmware before 3.0.0.4.38
62
This week
CRITICAL 9.8REMOTEMITIGATEMITIGATEMITIGATE
CVE-2018-8826 is a critical-severity flaw (CVSS 9.8) affecting rt-ac51u firmware, rt-ac58u firmware, rt-ac66u firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
ASUS RT-AC51U, RT-AC58U, RT-AC66U, RT-AC1750, RT-ACRH13, and RT-N12 D1 routers with firmware before 3.0.0.4.380.8228; RT-AC52U B1, RT-AC1200 and RT-N600 routers with firmware before 3.0.0.4.380.10446; RT-AC55U and RT-AC55UHP routers with firmware before 3.0.0.4.382.50276; RT-AC86U and RT-AC2900 routers with firmware before 3.0.0.4.384.20648; and possibly other RT-series routers allow remote attackers to execute arbitrary code via unspecified vect
Why this priority
Critical severity
EPSS top 9%: very likely to be exploited
Remotely exploitable, no login, no user action
No fix is published yet: follow the downgrade or mitigation steps.
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
Published CVE record published
Updated Record last modified
asus rt-ac51u firmware MITIGATE
Affected: 3.0.0.4.380.8228
Fixed in: no fixed release known
Safe to downgrade to: a release before 3.0.0.4.380.8228
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.
asus rt-ac58u firmware MITIGATE
Affected: 3.0.0.4.380.8228
Fixed in: no fixed release known
Safe to downgrade to: a release before 3.0.0.4.380.8228
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.
asus rt-ac66u firmware MITIGATE
Affected: 3.0.0.4.380.8228
Fixed in: no fixed release known
Safe to downgrade to: a release before 3.0.0.4.380.8228
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.
asus rt-ac1750 firmware MITIGATE
Affected: 3.0.0.4.380.8228
Fixed in: no fixed release known
Safe to downgrade to: a release before 3.0.0.4.380.8228
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.
asus rt-n12 d1 firmware MITIGATE
Affected: 3.0.0.4.380.8228
Fixed in: no fixed release known
Safe to downgrade to: a release before 3.0.0.4.380.8228
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.
asus rt-ac52u b1 firmware MITIGATE
Affected: 3.0.0.4.380.10446
Fixed in: no fixed release known
Safe to downgrade to: a release before 3.0.0.4.380.10446
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 sourceNVD · 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-2018-8826?
rt-ac51u firmware: mitigate or apply the listed mitigation; rt-ac58u firmware: mitigate or apply the listed mitigation; rt-ac66u firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2018-8826 being exploited?
CVE-2018-8826 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-2018-8826 affect?
CVE-2018-8826 affects rt-ac51u firmware, rt-ac58u firmware, rt-ac66u firmware. Severity is critical (CVSS 9.8). ASUS RT-AC51U, RT-AC58U, RT-AC66U, RT-AC1750, RT-ACRH13, and RT-N12 D1 routers with firmware before 3.0.0.4.380.8228; RT-AC52U B1, RT-AC1200 and RT-N600 routers with firmware before 3.0.0.4.380.10446; RT-AC55U and RT-AC55UHP routers with fi
How urgent is CVE-2018-8826?
Priority 62/100. Critical severity; EPSS top 9%: very likely to be exploited; Remotely exploitable, no login, no user action
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