CVE-2026-20473: Use After Free in Mediatek MediaTek chipset

3

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

—

No EPSS score.

Affects

Mediatek

MediaTek chipset and 17 more

CVSS base

6.0

Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

No

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Mediatek MediaTek chipset, Mediatek Mt6991 Firmware, Mediatek Mt6993 Firmware…).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Mediatek	MediaTek chipset	version MT8678version MT6993version MT8126version MT8171version MT8188version MT8189version MT8367version MT8668 and 9 more version MT8676version MT6991version MT8766version MT8768version MT8781version MT8786version MT8791Tversion MT8799version MT8910	Vulnerable	CVE Program (cve.org) e CISA ADP
Mediatek	Mt6991 Firmware	versions not specified by the source	Vulnerable	NIST National Vulnerability Database
Mediatek	Mt6993 Firmware	versions not specified by the source	Vulnerable	NIST National Vulnerability Database
Mediatek	Mt8126 Firmware	versions not specified by the source	Vulnerable	NIST National Vulnerability Database
Mediatek	Mt8171 Firmware	versions not specified by the source	Vulnerable	NIST National Vulnerability Database
Mediatek	Mt8188 Firmware	versions not specified by the source	Vulnerable	NIST National Vulnerability Database
Mediatek	Mt8189 Firmware	versions not specified by the source	Vulnerable	NIST National Vulnerability Database
Mediatek	Mt8367 Firmware	versions not specified by the source	Vulnerable	NIST National Vulnerability Database
Mediatek	Mt8668 Firmware	versions not specified by the source	Vulnerable	NIST National Vulnerability Database
Mediatek	Mt8676 Firmware	versions not specified by the source	Vulnerable	NIST National Vulnerability Database
Mediatek	Mt8678 Firmware	versions not specified by the source	Vulnerable	NIST National Vulnerability Database
Mediatek	Mt8766 Firmware	versions not specified by the source	Vulnerable	NIST National Vulnerability Database
Mediatek	Mt8768 Firmware	versions not specified by the source	Vulnerable	NIST National Vulnerability Database
Mediatek	Mt8781 Firmware	versions not specified by the source	Vulnerable	NIST National Vulnerability Database
Mediatek	Mt8786 Firmware	versions not specified by the source	Vulnerable	NIST National Vulnerability Database
Mediatek	Mt8791t Firmware	versions not specified by the source	Vulnerable	NIST National Vulnerability Database
Mediatek	Mt8799 Firmware	versions not specified by the source	Vulnerable	NIST National Vulnerability Database
Mediatek	Mt8910 Firmware	versions not specified by the source	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

Low

Privileges required

High

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
6.0	CVSS 3.1	Medium	0.8	5.2	134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database
6.0	CVSS 3.1	Medium	—	—	CISA-ADP via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N (score shown at the top: 134c704f-9b21-4f2e-91b3-4a467353bcc0)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-416 · Use After Free

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.

endpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

2026
Affected products added · mediatek, inc./mediatek chipset
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 15, 2026
CVSS changed · 6.0
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Aug 3, 2026 · MediaTek

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

1 on the record

www.mediatek.com/product-security-bulletin/August-2026
Vendor Advisory, NIST National Vulnerability Database

Elsewhere on this site

Mediatek
every CVE for this vendor

Memory corruption
same class

CWE-416
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-20588 Out-of-bounds Write in Mediatek Mt2718 Firmware 11d
Medium CVE-2026-20589 Out-of-bounds Write in Mediatek Mt2718 Firmware 11d
Medium CVE-2026-20587 Type Confusion in Mediatek Mt2718 Firmware 11d
High CVE-2026-20586 Out-of-bounds Write in Mediatek Mt8910 Firmware 11d
Medium CVE-2026-20542 Use After Free in Mediatek Mt2718 Firmware 11d
Medium CVE-2026-20541 In Modem, there is a possible out of bounds read due to a missing permission check. This… 11d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No FIRST EPSS score.
No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-20473 is "Use After Free in Mediatek MediaTek chipset", rated Medium. It affects MediaTek chipset (Mediatek); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.0 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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