# CVE-2026-20557: CVE-2026-20557

Status: published. Published: 2026-11-02. Updated: 2026-11-02.

In Modem, there is a possible out of bounds write due to a missing bounds check. This could lead to remote escalation of privilege, if a UE has connected to a rogue base station controlled by the attacker, with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: MOLY01877236; Issue ID: MSV-9804.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- MediaTek, Inc. / MediaTek chipset: MT2716 (affected); MT6813 (affected); MT6815 (affected); MT6835 (affected); MT6858 (affected); MT6878 (affected); MT6881 (affected); MT6897 (affected); MT6899 (affected); MT6982 (affected); MT6986 (affected); MT6988 (affected); MT6991 (affected); MT6993 (affected); MT8668 (affected); MT8676 (affected); MT8678 (affected); MT8755 (affected); MT8775 (affected); MT8792 (affected); MT8793 (affected); MT8863 (affected); MT8873 (affected); MT8875 (affected); MT8883 (affected). Source: CNA: MediaTek

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-787

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://www.mediatek.com/product-security-bulletin/November-2026 (CNA: MediaTek)

## Provenance

- CNA: MediaTek: https://www.cve.org/CVERecord?id=CVE-2026-20557; retrieved 2026-11-02; source updated 2026-11-02

Revision: 81bf68bc65e8d5bd9a7d9da23c4a0c4fae5b6980e0c8f7a2dd1acfc9db159793

Canonical: https://y2.dev/cve/CVE-2026-20557