PatchTheCEVCVE-2026-20493: In wifi, there is a possible out of bounds write due to a missing bounds check
16
Routine
MEDIUM 4.4MITIGATEMITIGATEMITIGATE
CVE-2026-20493 is a medium-severity flaw (CVSS 4.4) affecting mt6890 firmware, mt6988 firmware, mt6990 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
In wifi, there is a possible out of bounds write due to a missing bounds check. This could lead to local denial of service if a malicious actor has already obtained the System privilege. User interaction is not needed for exploitation. Patch ID: BORA00154903; Issue ID: MSV-7575.
Why this priority
- No elevated risk signals yet
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 4.4 (Medium) |
| Attack vector | Local |
| Attack complexity | Low |
| Privileges needed | High |
| User interaction | None |
| EPSS exploit chance | 0.1% (top 97%) |
| CISA exploited list | No |
| Weakness | CWE-787 |
| Published | 2026-08-03 |
| Last modified | 2026-10-23 |
Publisher (CNA): MediaTek, Inc. · Vendor: mediatek
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
mediatek mt6890 firmware MITIGATE
Affected: all versions
Fixed in: no fixed release known
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.
mediatek mt6988 firmware MITIGATE
Affected: all versions
Fixed in: no fixed release known
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.
mediatek mt6990 firmware MITIGATE
Affected: all versions
Fixed in: no fixed release known
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.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
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- CVE-2026-20480 MEDIUM 5.5 MITIGATE MITIGATE In Audio HAL, there is a possible out of bounds write due to a heap buffer overflow
- CVE-2026-20491 MEDIUM 5.5 MITIGATE MITIGATE In med, there is a possible out of bounds write due to an incorrect bounds check
- CVE-2026-20492 MEDIUM 5.5 MITIGATE MITIGATE In Audio HAL, there is a possible system becoming unresponsive due to a race condition
- CVE-2026-20494 MEDIUM 5.5 MITIGATE MITIGATE In wifi, there is a possible out of bounds read due to a missing bounds check