🛡️ CVE-2026-20491 — mt2735-firmware

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

• Attack vector: Local — a local account, shell or session on the host is needed.
• Attack complexity: Low — the attack works reliably, with no preparation.
• Privileges required: Low — an ordinary user account is enough.
• User interaction: None — nobody has to be tricked into anything.
• Scope: Unchanged — the damage stays inside the vulnerable component.
• Confidentiality impact: None.
• Integrity impact: None.
• Availability impact: High — total loss, or loss the attacker controls.

Weakness class

CVE-2026-20491 is classified as CWE-787: Out-of-bounds Write. Data is written past the end or before the start of a buffer, corrupting whatever is stored there.

Affected software

CVE-2026-20491 is recorded against 5 packages.

• mt2735-firmware
• mt2737-firmware
• mt6890-firmware
• mt6988-firmware
• mt6990-firmware

Timeline and source

Published on 3 August 2026 and last revised on 19 August 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

www.mediatek.com

Other advisories for this package

mt2735-firmware has other advisories on record. If you are patching this one, these are worth checking on the same host:

• CVE-2026-20479 (7.5 High, published 3 Aug 2026)
• CVE-2026-20492 (5.5 Medium, published 3 Aug 2026)
• CVE-2026-20480 (5.5 Medium, published 3 Aug 2026)
• CVE-2026-20450 (6.5 Medium, published 4 May 2026)
• CVE-2026-20449 (6.5 Medium, published 4 May 2026)
• CVE-2026-20433 (8.8 High, published 7 Apr 2026)
• CVE-2026-20432 (8.0 High, published 7 Apr 2026)
• CVE-2025-20659 (6.5 Medium, published 7 Apr 2025)

Same weakness in other software

These advisories are the same class of weakness (CWE-787: Out-of-bounds Write) in other software:

• CVE-2017-12605 (8.0 High, published 9 Jul 2026)
• CVE-2022-29208 (8.0 High, published 9 Jul 2026)
• CVE-2022-23561 (8.0 High, published 9 Jul 2026)
• CVE-2019-9423 (8.0 High, published 9 Jul 2026)
• CVE-2018-5268 (published 9 Jul 2026)
• CVE-2017-12606 (8.0 High, published 9 Jul 2026)
• CVE-2019-5063 (8.0 High, published 9 Jul 2026)
• CVE-2017-12603 (8.0 High, published 2 Jul 2026)

Details

Affected Packages

References