CVE-2026-36738: U-SPEED AC1200 Gigabit Wi-Fi Router (Model: T18-21K) V1.0 is vulnerable to Incorrect Access Control

Routine

MEDIUM 6.8MITIGATE

CVE-2026-36738 is a medium-severity flaw (CVSS 6.8) affecting t18-21k firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

U-SPEED AC1200 Gigabit Wi-Fi Router (Model: T18-21K) V1.0 is vulnerable to Incorrect Access Control. The device exposes a UART interface that lacks authentication, authorization, or access control mechanisms. An attacker with physical access to the UART pins can connect to the interface and gain unrestricted access to device functionality.

Why this priority

Public exploit reference

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

Risk facts

CVSS score	6.8 (Medium)
Attack vector	Physical
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 78%)
CISA exploited list	No
Weakness	CWE-284
Published	2026-05-13
Last modified	2026-06-30

Publisher (CNA): MITRE · Vendor: u-speed

Last updated 2026-06-30 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-13 16:16 UTCPublished CVE record published
2026-06-30 19:02 UTCUpdated Record last modified

u-speed t18-21k firmware MITIGATE

Affected: 1.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0

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-2026-36738?

t18-21k firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-36738 being exploited?

CVE-2026-36738 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-2026-36738 affect?

CVE-2026-36738 affects t18-21k firmware. Severity is medium (CVSS 6.8). U-SPEED AC1200 Gigabit Wi-Fi Router (Model: T18-21K) V1.0 is vulnerable to Incorrect Access Control. The device exposes a UART interface that lacks authentication, authorization, or access control mechanisms. An attacker with physical acces

How urgent is CVE-2026-36738?

Priority 34/100. Public exploit reference

Software pages

Wi-Fi vulnerabilities

Related CVEs

CVE-2026-36741 HIGH 7.2 MITIGATE U-SPEED AC1200 Gigabit Wi-Fi Router (Model: T18-21K) V1.0 is vulnerable to Command Injection

References

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