{"id":"CVE-2026-20548","kind":"vulnerability","aliases":["CVE-2026-20548"],"related":[],"title":"Modem: out-of-bounds write lets a rogue base station take control","description":"In Modem, there is a possible out of bounds write due to an integer overflow. 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: MOLY01872867 / MOLY01774038; Issue ID: MSV-9801.","summary":"A integer overflow in modem firmware causes an out-of-bounds write that can be triggered when a phone or device connects to an attacker-controlled rogue base station. Successful exploitation can lead to escalation of privilege on the modem without user interaction.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["cellular","infrastructure","mobile-devices","modem"],"not_affected_if":["no-affected-modem"],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-11-02T03:17:31+00:00","first_seen_at":"2026-11-02T03:31:24+00:00","triaged_at":"2026-11-02T03:33:58+00:00","updated_at":"2026-11-02T03:33:58+00:00","category":"infrastructure","confidence":0.5,"triage":{"at":"2026-11-02T03:33:58Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Modem: out-of-bounds write lets a rogue base station take control","impact":"high","summary":"A integer overflow in modem firmware causes an out-of-bounds write that can be triggered when a phone or device connects to an attacker-controlled rogue base station. Successful exploitation can lead to escalation of privilege on the modem without user interaction.","audience":"everyone","category":"infrastructure","nicknames":[],"who_cares":["modem","cellular","mobile-devices"],"confidence":0.5,"fix_status":"unknown","needs_auth":"no","worst_case":"attacker escalates privileges on the modem remotely via rogue base station","analyst_note":"Find the vendor bulletin (MediaTek) listing affected chipsets, firmware versions and patched builds for MSV-9801.","how_to_check":"- unknown","plain_action":"Install your phone or device's latest software update once the vendor publishes a fix for this modem flaw.","needs_analyst":true,"not_affected_if":["no-affected-modem"],"who_is_affected":"Devices with the affected modem firmware that connect to cellular networks are exposed when a rogue base station is in range. Systems that do not use an affected cellular modem, or that are not connecting to untrusted base stations, are less exposed. unknown for the exact product list.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000661,"input_tokens":4129,"output_tokens":496,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':15A,18A '-20548':16A,19A '-9801':128C 'addit':110C 'attack':52B,107C 'attacker-control':51B 'base':10A,55B,102C 'bound':5A,37B,79C 'caus':32B 'cellular':20B 'connect':48B,98C 'control':13A,53B,104C 'could':87C 'cve':14A,17A 'devic':24B,47B 'due':81C 'escal':62B,91C 'execut':111C 'exploit':58B,120C 'firmwar':31B 'id':122C,126C 'infrastructur':21B 'integ':27B,84C 'interact':70B,115C 'issu':125C 'lead':60B,88C 'let':7A 'mobil':23B 'mobile-devic':22B 'modem':1A,25B,30B,67B,72C 'moly01774038':124C 'moly01872867':123C 'msv':127C 'need':113C,118C 'out-of-bound':2A,34B 'overflow':28B,85C 'patch':121C 'phone':45B 'possibl':76C 'privileg':64B,93C,112C 'remot':90C 'rogu':9A,54B,101C 'station':11A,56B,103C 'success':57B 'take':12A 'trigger':42B 'ue':96C 'user':69B,114C 'without':68B 'write':6A,38B,80C","nicknames":[],"mitigations":[],"who_affected":"Devices with the affected modem firmware that connect to cellular networks are exposed when a rogue base station is in range. Systems that do not use an affected cellular modem, or that are not connecting to untrusted base stations, are less exposed. unknown for the exact product list.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"unknown","audience":"everyone","plain_action":"Install your phone or device's latest software update once the vendor publishes a fix for this modem flaw.","pkeys":[],"ptokens":[],"labels":["cellular","infrastructure","mobiledevices","modem","unknown"],"first_public_at":"2026-11-02T03:17:31+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-20548","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-20548","severity":null,"published_at":"2026-11-02T03:17:31+00:00","modified_at":"2026-11-02T03:17:31+00:00","first_seen_at":"2026-11-02T03:31:24+00:00","fetched_at":"2026-11-02T03:31:24+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}