{"id":"CVE-2026-119053","kind":"vulnerability","aliases":["CVE-2026-119053"],"related":[],"title":"lwIP SNMP agent: fragmented requests leak adjacent memory in responses","description":"lwIP 2.0.0 through 2.2.1 built with the SNMP agent contains an out-of-bounds read vulnerability in snmp_pbuf_stream_writeto() that bounds copies by pbuf->len instead of remaining bytes. Remote unauthenticated attackers knowing the read community can send fragmented SNMP requests to receive adjacent receive-buffer or pool memory echoed in responses.","summary":"lwIP versions 2.0.0 through 2.2.1, built with the SNMP agent enabled, copy too many bytes when handling fragmented SNMP requests. A remote attacker who knows the read community string can get adjacent receive-buffer or pool memory echoed back in responses.","severity":"medium","cvss":6.9,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["embedded","infrastructure","iot-firmware","lwip","snmp"],"not_affected_if":["lwip-outside-2.0.0-2.2.1","snmp-agent-disabled","snmp-not-network-reachable"],"how_to_check":"- Check whether the build includes the lwIP SNMP agent (`LWIP_SNMP` enabled in the lwIP configuration)\n- Check the lwIP version in the firmware or source tree against `2.0.0` through `2.2.1`","fix":null,"status":"open","published_at":"2026-10-29T14:17:52+00:00","first_seen_at":"2026-10-29T14:25:23+00:00","triaged_at":"2026-10-29T14:25:56+00:00","updated_at":"2026-10-29T14:25:56+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-29T14:25:56Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"lwIP SNMP agent: fragmented requests leak adjacent memory in responses","impact":"low","summary":"lwIP versions 2.0.0 through 2.2.1, built with the SNMP agent enabled, copy too many bytes when handling fragmented SNMP requests. A remote attacker who knows the read community string can get adjacent receive-buffer or pool memory echoed back in responses.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["lwip","embedded","snmp","iot-firmware"],"confidence":0.6,"fix_status":"unknown","needs_auth":"yes","worst_case":"Memory contents from the device leak in SNMP responses","analyst_note":"Check the NVD entry and the lwIP project advisory for the fixed version and whether the flaw is in a released tag.","how_to_check":"- Check whether the build includes the lwIP SNMP agent (`LWIP_SNMP` enabled in the lwIP configuration)\n- Check the lwIP version in the firmware or source tree against `2.0.0` through `2.2.1`\n- unknown for anything beyond this, the sources do not say","plain_action":"","needs_analyst":true,"not_affected_if":["snmp-agent-disabled","lwip-outside-2.0.0-2.2.1","snmp-not-network-reachable"],"who_is_affected":"Only devices or software built on lwIP 2.0.0 through 2.2.1 with the SNMP agent compiled in are exposed. The attacker must reach the SNMP port and know the read community string, so systems with SNMP disabled, or reachable only from trusted management networks, are much less exposed. Embedded firmware is the usual place this lives and may be hard to update.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"medium"},"cost_usd":0.00074,"input_tokens":4173,"output_tokens":645,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-119053':13A,16A '-2026':12A,15A '2.0.0':26B,67C '2.2.1':28B,69C 'adjac':7A,55B,112C 'agent':3A,33B,74C 'attack':46B,100C 'back':63B 'bound':80C,89C 'buffer':58B,115C 'built':29B,70C 'byte':38B,97C 'communiti':51B,104C 'contain':75C 'copi':35B,90C 'cve':11A,14A 'echo':62B,119C 'embed':17B 'enabl':34B 'firmwar':21B 'fragment':4A,41B,107C 'get':54B 'handl':40B 'infrastructur':18B 'instead':94C 'iot':20B 'iot-firmwar':19B 'know':48B,101C 'leak':6A 'len':93C 'lwip':1A,22B,24B,66C 'mani':37B 'memori':8A,61B,118C 'out-of-bound':77C 'pbuf':85C,92C 'pool':60B,117C 'read':50B,81C,103C 'receiv':57B,111C,114C 'receive-buff':56B,113C 'remain':96C 'remot':45B,98C 'request':5A,43B,109C 'respons':10A,65B,121C 'send':106C 'snmp':2A,23B,32B,42B,73C,84C,108C 'stream':86C 'string':52B 'unauthent':99C 'version':25B 'vulner':82C 'writeto':87C","nicknames":[],"mitigations":[],"who_affected":"Only devices or software built on lwIP 2.0.0 through 2.2.1 with the SNMP agent compiled in are exposed. The attacker must reach the SNMP port and know the read community string, so systems with SNMP disabled, or reachable only from trusted management networks, are much less exposed. Embedded firmware is the usual place this lives and may be hard to update.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"first_public_at":"2026-10-29T14:17:52+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_by":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-119053","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-119053","severity":null,"published_at":"2026-10-29T14:17:52+00:00","modified_at":"2026-10-29T14:17:52+00:00","first_seen_at":"2026-10-29T14:25:23+00:00","fetched_at":"2026-10-29T14:25:23+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"}