CVE-2026-0139: In Modem, there is a possible out of bounds write due to a missing bounds check

Synopsis

An out-of-bounds write vulnerability exists in the Android kernel Modem component due to a missing bounds check. The flaw is reachable over the network by any authenticated low-privilege user without requiring any interaction from a victim, derived from the CVSS vector (AV:N/AC:L/PR:L/UI:N). Successful exploitation gives the attacker full remote code execution on the affected device. No fix version has been published yet; HarborGuard tracks the upstream advisory and will surface a patched-image rebuild as soon as one becomes available.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The attacker must be able to reach the Modem service over the network; there is no local or physical access requirement.

• AuthenticationRequired

  A low-privilege account is sufficient; no administrative or elevated credentials are needed to trigger the vulnerability.

• Victim interactionNot required

  No action from any user on the target device is required for exploitation.

• Attack complexityDetail

  The exploit is reliable and condition-free; no race conditions or specific memory layout prerequisites are involved.

Blast Radius

• A successful attacker achieves remote code execution within the Modem component of the Android kernel.
• The high Confidentiality impact means the attacker reads arbitrary memory regions, including stored credentials, session material, and user data processed by the modem.
• The high Integrity impact means the attacker writes arbitrary data into modem memory, modifying firmware state, configuration, or persisted records.
• The high Availability impact means the attacker can crash or render the modem subsystem inoperable, causing complete loss of cellular connectivity on the affected device.