Samsung Dialer CVE-2026-21061

User interaction is explicitly required - the target must interact with attacker-controlled content within the Samsung Dialer application; passive delivery alone is insufficient to trigger exploitation. The CVSS 4.0 AT:P metric indicates that specific attack prerequisites must be met beyond mere network access, though Samsung has not publicly disclosed the exact device state or configuration required. High attack complexity (AC:H) means the attacker cannot reliably trigger the vulnerable code path on demand without satisfying these undisclosed prerequisites. Exploitation is further constrained to Samsung Mobile Devices running Samsung Dialer prior to SMR Aug-2026 Release 1. The impact is strictly limited to confidentiality - specifically read access to SIM-related functions - with no integrity or availability effect confirmed. There is no indication that default Samsung configurations are immune; the vulnerability appears to affect standard Dialer deployments.

The CVSS 4.0 score of 6.0 reflects a genuine but bounded risk. The AV:N metric confirms network reachability, and VC:H signals that SIM data - potentially including IMSI or subscriber identity - is fully exposed on successful exploitation. However, AC:H (high attack complexity) and AT:P (specific prerequisites required) indicate that exploitation is non-trivial and not reliably repeatable without meeting undisclosed conditions, which substantially lowers mass-exploitation potential. UI:P mandates that the target user must interact with attacker-supplied content, adding a social engineering dependency. There is no KEV listing and no confirmed public exploit code, which is consistent with the AC:H/AT:P profile - this is a targeted rather than opportunistic threat. Impact is confidentiality-only (VI:N/VA:N), meaning the attack yields data exposure but does not allow arbitrary code execution or denial of service. Overall, this is a medium-priority issue requiring attention primarily for high-value targets (government officials, executives) where SIM identity leakage carries disproportionate risk (e.g., SIM-swap facilitation); for general enterprise fleets, standard patch-cycle prioritization is appropriate.

An attacker crafts a malicious payload - such as a specially formatted phone number, SIM toolkit command, or deep-link URI - that is delivered to the target via SMS, messaging application, or network-based mechanism. When the victim interacts with the content in the Samsung Dialer (e.g., tapping a number or accepting a call prompt), the improper input validation allows the attacker-controlled input to invoke privileged SIM-related functions, exposing subscriber identity data such as IMSI. No public exploit code has been identified at time of analysis.