{"id":"CVE-2026-20547","kind":"vulnerability","aliases":["CVE-2026-20547"],"related":[],"title":"Modem firmware: 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: MOLY01874018 / MOLY01774038; Issue ID: MSV-9802.","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 be pushed into a remote escalation of privilege without user interaction.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["android","baseband","infrastructure","mobile-devices","modem"],"not_affected_if":["no-cellular-modem"],"how_to_check":"- Check the modem or baseband firmware version on affected phones and devices against the vendor's patch notes","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: the sources cite patch IDs MOLY01874018 and MOLY01774038 but do not state which device or firmware versions they correspond to","reach":"network","title":"Modem firmware: 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 be pushed into a remote escalation of privilege without user interaction.","audience":"everyone","category":"infrastructure","nicknames":[],"who_cares":["modem","baseband","mobile-devices","android"],"confidence":0.5,"fix_status":"unknown","needs_auth":"no","worst_case":"Attacker gains elevated privileges on the device via a rogue base station","analyst_note":"Find which devices and firmware versions carry patch IDs MOLY01874018 and MOLY01774038, using the vendor bulletin for MSV-9802.","how_to_check":"- Check the modem or baseband firmware version on affected phones and devices against the vendor's patch notes\n- unknown for specific product ranges: the sources do not list affected devices or versions","plain_action":"Install the latest phone or modem firmware update from your device maker once it is released.","needs_analyst":true,"not_affected_if":["no-cellular-modem"],"who_is_affected":"Devices with the affected modem firmware that connect to cellular networks are exposed, since the attack uses a rogue base station rather than the internet. The sources do not list the affected devices or chipsets. Systems that never use a cellular modem are not affected.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000706,"input_tokens":4131,"output_tokens":586,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':15A,18A '-20547':16A,19A '-9802':124C 'addit':106C 'allow':35B 'android':20B 'attack':49B,103C 'attacker-control':48B 'base':11A,52B,98C 'baseband':21B 'bound':6A,29B,40B,74C,80C 'check':30B,81C 'connect':45B,94C 'control':50B,100C 'could':83C 'cve':14A,17A 'devic':25B,43B 'due':76C 'escal':60B,87C 'execut':107C 'exploit':116C 'firmwar':2A,34B 'id':118C,122C 'infrastructur':22B 'interact':65B,111C 'issu':121C 'lead':84C 'let':8A 'miss':28B,79C 'mobil':24B 'mobile-devic':23B 'modem':1A,26B,33B,67C 'moly01774038':120C 'moly01874018':119C 'msv':123C 'need':109C,114C 'out-of-bound':3A,37B 'patch':117C 'possibl':71C 'privileg':62B,89C,108C 'push':56B 'remot':59B,86C 'rogu':10A,51B,97C 'station':12A,53B,99C 'take':13A 'ue':92C 'user':64B,110C 'without':63B 'write':7A,41B,75C","nicknames":[],"mitigations":[],"who_affected":"Devices with the affected modem firmware that connect to cellular networks are exposed, since the attack uses a rogue base station rather than the internet. The sources do not list the affected devices or chipsets. Systems that never use a cellular modem are not affected.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"unknown","audience":"everyone","plain_action":"Install the latest phone or modem firmware update from your device maker once it is released.","pkeys":[],"ptokens":[],"labels":["android","baseband","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-2026-20547","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-20547","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"}