How severe is CVE-2026-20408?

CVE-2026-20408 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-20408 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-20408?

CVE-2026-20408 primarily affects Mediatek Software Development Kit. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-20408?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-20408 have an EU (EUVD) identifier?

Yes. CVE-2026-20408 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-5129.

When was CVE-2026-20408 published?

CVE-2026-20408 was published on 2026-02-02 and last updated on 2026-06-17.

CVE-2026-20408

CVE-2026-20408 is a high-severity vulnerability in Mediatek Software Development Kit with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 0% (18th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-5129
Weakness: CWE-787
Affected product: Mediatek Software Development Kit
Published: 2026-02-02
Last modified: 2026-06-17

Description

In wlan, there is a possible out of bounds write due to a heap buffer overflow. This could lead to remote (proximal/adjacent) escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: WCNCR00461651; Issue ID: MSV-4758.

Frequently asked questions

What is CVE-2026-20408?: In wlan, there is a possible out of bounds write due to a heap buffer overflow. This could lead to remote (proximal/adjacent) escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: WCNCR00461651; Issue ID: MSV-4758.
How severe is CVE-2026-20408?: CVE-2026-20408 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-20408 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-20408?: CVE-2026-20408 primarily affects Mediatek Software Development Kit. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-20408?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-20408 have an EU (EUVD) identifier?: Yes. CVE-2026-20408 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-5129.
When was CVE-2026-20408 published?: CVE-2026-20408 was published on 2026-02-02 and last updated on 2026-06-17.

References

https://corp.mediatek.com/product-security-bulletin/February-2026

Affected products (4)

cpe:2.3:a:mediatek:software_development_kit:*:*:*:*:*:*:*:*
cpe:2.3:o:openwrt:openwrt:19.07.0:-:*:*:*:*:*:*
cpe:2.3:o:openwrt:openwrt:21.02.0:-:*:*:*:*:*:*
cpe:2.3:o:openwrt:openwrt:23.05.0:-:*:*:*:*:*:*

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