{"id":"CVE-2026-20545","kind":"vulnerability","aliases":["CVE-2026-20545"],"related":[],"title":"Modem: out-of-bounds write lets a rogue base station take over","description":"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: MOLY01879158 / MOLY01774038; Issue ID: MSV-9811.","summary":"A missing bounds check in the modem firmware allows an out-of-bounds write. A device that connects to an attacker-controlled rogue base station can have its privileges escalated remotely, with no user interaction and no extra execution privileges needed.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["cellular","infrastructure","mobile-devices","modem"],"not_affected_if":["no-cellular-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":"2026-11-02T03:33:59+00:00","updated_at":"2026-11-02T03:33:59+00:00","category":"infrastructure","confidence":0.5,"triage":{"at":"2026-11-02T03:33:59Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Modem: out-of-bounds write lets a rogue base station take over","impact":"high","summary":"A missing bounds check in the modem firmware allows an out-of-bounds write. A device that connects to an attacker-controlled rogue base station can have its privileges escalated remotely, with no user interaction and no extra execution privileges needed.","audience":"everyone","category":"infrastructure","nicknames":[],"who_cares":["modem","mobile-devices","cellular"],"confidence":0.5,"fix_status":"unknown","needs_auth":"no","worst_case":"Attacker escalates privileges on the device after a rogue base station connection","analyst_note":"Find the affected device and chipset list and the vendor patch level from the Android or MediaTek bulletin matching patch IDs MOLY01879158 and MOLY01774038 (issue MSV-9811).","how_to_check":"- unknown","plain_action":"Install the latest phone software update from your device maker as soon as it is available.","needs_analyst":true,"not_affected_if":["no-cellular-modem"],"who_is_affected":"Devices with the affected modem firmware that connect to cellular networks are potentially exposed, since the attack works by a rogue base station. The sources do not name specific devices or chipset versions, so the exact affected set is unknown. Systems that never use the cellular modem are not affected.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000669,"input_tokens":4131,"output_tokens":512,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':14A,17A '-20545':15A,18A '-9811':126C 'addit':108C 'allow':33B 'attack':47B,105C 'attacker-control':46B 'base':10A,50B,100C 'bound':5A,27B,38B,76C,82C 'cellular':19B 'check':28B,83C 'connect':43B,96C 'control':48B,102C 'could':85C 'cve':13A,16A 'devic':23B,41B 'due':78C 'escal':56B,89C 'execut':65B,109C 'exploit':118C 'extra':64B 'firmwar':32B 'id':120C,124C 'infrastructur':20B 'interact':61B,113C 'issu':123C 'lead':86C 'let':7A 'miss':26B,81C 'mobil':22B 'mobile-devic':21B 'modem':1A,24B,31B,69C 'moly01774038':122C 'moly01879158':121C 'msv':125C 'need':67B,111C,116C 'out-of-bound':2A,35B 'patch':119C 'possibl':73C 'privileg':55B,66B,91C,110C 'remot':57B,88C 'rogu':9A,49B,99C 'station':11A,51B,101C 'take':12A 'ue':94C 'user':60B,112C 'write':6A,39B,77C","nicknames":[],"mitigations":[],"who_affected":"Devices with the affected modem firmware that connect to cellular networks are potentially exposed, since the attack works by a rogue base station. The sources do not name specific devices or chipset versions, so the exact affected set is unknown. Systems that never use the cellular modem are not affected.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"unknown","audience":"everyone","plain_action":"Install the latest phone software update from your device maker as soon as it is available.","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-2026-20545","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-20545","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"}