A flaw in how Unisoc's modem firmware validates network input can be triggered remotely, with no user interaction. Unisoc lists the T606 as affected. OhrTech devices now ship modem firmware that includes the fix.
What the vulnerability is
Unisoc reports a flaw in how its modem firmware validates input from the network. It can be triggered remotely, with no user interaction and no privileges, and Unisoc describes the impact as a possible system crash that "could lead to remote escalation of privilege". Unisoc rates it 7.5 (High) and lists the T606, T612 and T616 among the affected chips.
What we did
Modem firmware is a closed Unisoc binary, so this can only be fixed by shipping newer firmware. The Foundation OS ships modem firmware from a build at security patch level 2026-09-01, which covers CVE-2025-31718: Google lists the fix in the December 2025 Android Security Bulletin at patch level 2025-12-05.
Who needs to act
Nobody. The fix is part of the Foundation OS that every OhrTech device runs.
Credit
Unisoc disclosed this flaw in its October 2025 security bulletin and did not name who found it.
Timeline
- Unisoc publishes CVE-2025-31718 in its October 2025 security bulletin.
- Google lists the fix in the December 2025 Android Security Bulletin, at security patch level 2025-12-05.
- OhrTech publishes this bulletin; the updated modem firmware is part of the Foundation OS.