CVE-2026-20419: In wlan AP/STA firmware, there is a possible system becoming irresponsive due to an uncaught exception

Q: How do I fix CVE-2026-20419?

nbiot sdk: upgrade to newer than 3.6; software development kit: upgrade to newer than 7.6.7.2; openwrt: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2026-20419 being exploited?

CVE-2026-20419 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-2026-20419 affect?

CVE-2026-20419 affects nbiot sdk, software development kit, openwrt. Severity is medium (CVSS 6.5). In wlan AP/STA firmware, there is a possible system becoming irresponsive due to an uncaught exception. This could lead to remote (proximal/adjacent) denial of service with no additional execution privileges needed. User interaction is not

Q: How urgent is CVE-2026-20419?

Priority 37/100. No elevated risk signals yet.

Routine

MEDIUM 6.5UPGRADEUPGRADEMITIGATE

CVE-2026-20419 is a medium-severity flaw (CVSS 6.5) affecting nbiot sdk, software development kit, openwrt. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In wlan AP/STA firmware, there is a possible system becoming irresponsive due to an uncaught exception. This could lead to remote (proximal/adjacent) denial of service with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: WCNCR00461663 / WCNCR00463309; Issue ID: MSV-4852.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Adjacent network
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.8% (top 44%)
CISA exploited list	No
Weakness	CWE-754
Published	2026-02-02
Last modified	2026-06-17

Publisher (CNA): MediaTek, Inc. · Vendor: mediatek · openwrt

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-02-02 09:15 UTCPublished CVE record published
2026-06-17 10:17 UTCUpdated Record last modified

mediatek nbiot sdk UPGRADE

Affected: <= 3.6

Fixed in: newer than 3.6

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy nbiot-sdk || rpm -q nbiot-sdk || nbiot-sdk --version

2. UPGRADE to newer than 3.6 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade nbiot-sdk

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade nbiot-sdk

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

mediatek software development kit UPGRADE

Affected: <= 7.6.7.2

Fixed in: newer than 7.6.7.2

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy software-development-kit || rpm -q software-development-kit || software-development-kit --version

2. UPGRADE to newer than 7.6.7.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade software-development-kit

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade software-development-kit

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

openwrt openwrt MITIGATE

Affected: 19.07.0 · 21.02.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 19.07.0

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-2026-20419?

nbiot sdk: upgrade to newer than 3.6; software development kit: upgrade to newer than 7.6.7.2; openwrt: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-20419 being exploited?

CVE-2026-20419 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-2026-20419 affect?

CVE-2026-20419 affects nbiot sdk, software development kit, openwrt. Severity is medium (CVSS 6.5). In wlan AP/STA firmware, there is a possible system becoming irresponsive due to an uncaught exception. This could lead to remote (proximal/adjacent) denial of service with no additional execution privileges needed. User interaction is not

How urgent is CVE-2026-20419?

Priority 37/100. No elevated risk signals yet.

Software pages

OpenWrt vulnerabilities

Related CVEs

CVE-2026-20436 MEDIUM 6.7 UPGRADE In wlan STA driver, there is a possible escalation of privilege due to a missing bounds check
CVE-2026-20423 HIGH 7.8 UPGRADE In wlan STA driver, there is a possible out of bounds write due to a missing bounds check
CVE-2026-20407 CRITICAL 9.3 UPGRADE In wlan STA driver, there is a possible escalation of privilege due to a missing bounds check
CVE-2025-20687 MEDIUM 5.5 UPGRADE In Bluetooth driver, there is a possible out of bounds read due to an incorrect bounds check
CVE-2025-20680 CRITICAL 9.8 UPGRADE In Bluetooth driver, there is a possible out of bounds write due to an incorrect bounds check

References

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