{"id":"CVE-2026-113782","kind":"vulnerability","aliases":["CVE-2026-113782"],"related":[],"title":"ESP-IDF: crafted ICMPv6 packet overflows stack on Border Router","description":"ESP-IDF is the Espressif Internet of Things (IOT) Development Framework. From 5.2.0 until 5.2.8, 5.3.6, 5.4.5, 5.5.5, and 6.0.3, the OpenThread Border Router Neighbor Discovery packet handler trusts an attacker-controlled ICMPv6 option length while copying into a fixed stack buffer. A host on the same infrastructure link as the Border Router can send a crafted ICMPv6 Router Advertisement to its infrastructure interface whose oversized length causes an out-of-bounds write into adjacent stack memory. Firmware is affected only when CONFIG_OPENTHREAD_BORDER_ROUTER=y; Thread end devices, routers, and RCP firmware without the Border Router feature are unaffected. Exploitation requires no authentication or user interaction and can crash or reboot the device or corrupt adjacent stack state. This issue is fixed in versions 5.2.8, 5.3.6, 5.5.5, and 6.0.3 and is scheduled to be fixed in version 5.4.5.","summary":"ESP-IDF's OpenThread Border Router trusts an attacker-controlled ICMPv6 option length when copying Neighbor Discovery data into a fixed stack buffer. A host on the same infrastructure link can send a crafted Router Advertisement and cause an out-of-bounds stack write that can crash or reboot the device or corrupt adjacent stack state.","severity":"high","cvss":7.1,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"esp-idf","fixed":["5.2.8","5.3.6","5.5.5","6.0.3"],"affected":">= 5.2.0, < 5.2.8; >= 5.3.0, < 5.3.6; >= 5.4.0, <= 5.4.4; >= 5.5.0, < 5.5.5; >= 6.0.0, < 6.0.3","ecosystem":"vendor"}],"ecosystems":[],"tags":["embedded","esp-idf","iot","openthread","runtime","thread"],"not_affected_if":["default-config","end-device","no-border-router","rcp-firmware"],"how_to_check":"Check if your firmware sets CONFIG_OPENTHREAD_BORDER_ROUTER=y (in sdkconfig or via idf.py menuconfig; default is off). If it does, run 'idf.py --version' or check IDF_PATH git tag: affected are v5.2.0-5.2.7, v5.3.0-5.3.5, v5.4.0-5.4.4, v5.5.0-5.5.4, v6.0.0-6.0.2. Thread end devices, routers and RCP firmware without the Border Router option are not affected.","fix":"Upgrade ESP-IDF to 5.2.8, 5.3.6, 5.5.5 or 6.0.3 (released). 5.4.x: the fix is on release/v5.4 (commit 4068c4e) but 5.4.5 is not yet released per the advisory, so build from that branch until it ships. 6.1 and later are not affected. 5.1 and older are end of life and get no fix.","status":"open","published_at":"2026-11-04T19:17:18+00:00","first_seen_at":"2026-11-04T19:28:48+00:00","triaged_at":"2026-11-04T19:30:12+00:00","updated_at":"2026-11-04T19:32:05+00:00","category":"runtime","confidence":0.9,"triage":{"at":"2026-11-04T19:30:12Z","model":"claude-haiku-5-5","output":{"fix":"- ESP-IDF `5.2.8`, `5.3.6`, `5.5.5` and `6.0.3` per the source; 5.4.x fix is stated as scheduled for `5.4.5`.","reach":"network","title":"ESP-IDF: crafted ICMPv6 packet overflows stack on Border Router","impact":"medium","summary":"ESP-IDF's OpenThread Border Router trusts an attacker-controlled ICMPv6 option length when copying Neighbor Discovery data into a fixed stack buffer. A host on the same infrastructure link can send a crafted Router Advertisement and cause an out-of-bounds stack write that can crash or reboot the device or corrupt adjacent stack state.","audience":"businesses","category":"runtime","nicknames":[],"who_cares":["esp-idf","iot","thread","openthread","embedded"],"confidence":0.7,"fix_status":"available","needs_auth":"no","worst_case":"device crashes, reboots, or adjacent stack state is corrupted","analyst_note":"Confirm the 5.4.x fixed version; the source says only 'scheduled to be fixed in 5.4.5', so check the vendor advisory linked on GitHub.","how_to_check":"- Check whether firmware is built with `CONFIG_OPENTHREAD_BORDER_ROUTER=y` in the project's sdkconfig.\n- Check the ESP-IDF version in use, for example with `idf.py --version`; affected ranges are 5.2.0 to 5.2.8, 5.3.0 to 5.3.6, 5.4.0 to 5.4.5, 5.5.0 to 5.5.5 and 6.0.0 to 6.0.3.","plain_action":"","needs_analyst":true,"not_affected_if":["default-config","no-border-router","rcp-firmware","end-device"],"who_is_affected":"Only firmware built with the OpenThread Border Router feature enabled is exposed; Thread end devices, routers and RCP firmware without that feature are not affected. The attacker must be on the same infrastructure link as the Border Router, so devices on isolated networks are less exposed. Teams that ship IoT products on ESP-IDF should check their build configuration.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000847,"input_tokens":4480,"output_tokens":797,"severity_before":"high"},"analyst_status":"done","analyst_note":"Confirm the 5.4.x fixed version; the source says only 'scheduled to be fixed in 5.4.5', so check the vendor advisory linked on GitHub.","search":"'-113782':14A,17A '-2026':13A,16A '5.2.0':101C '5.2.8':103C,217C '5.3.6':104C,218C '5.4.5':105C,230C '5.5.5':106C,219C '6.0.3':108C,221C 'adjac':85B,165C,208C 'advertis':66B,149C 'affect':170C 'attack':39B,120C 'attacker-control':38B,119C 'authent':195C 'border':10A,34B,111C,141C,175C,187C 'bound':73B,162C 'buffer':53B,131C 'caus':68B,157C 'config':173C 'control':40B,121C 'copi':45B,126C 'corrupt':84B,207C 'craft':4A,64B,146C 'crash':78B,201C 'cve':12A,15A 'data':48B 'develop':98C 'devic':82B,180C,205C 'discoveri':47B,114C 'embed':21B 'end':179C 'esp':2A,19A,23B,30B,89C 'esp-idf':1A,18A,22B,29B,88C 'espressif':93C 'exploit':192C 'featur':189C 'firmwar':168C,184C 'fix':51B,129C,214C,227C 'framework':99C 'handler':116C 'host':55B,133C 'icmpv6':5A,41B,122C,147C 'idf':3A,20A,24B,31B,90C 'infrastructur':59B,137C,152C 'interact':198C 'interfac':153C 'internet':94C 'iot':25B,97C 'issu':212C 'length':43B,124C,156C 'link':60B,138C 'memori':167C 'neighbor':46B,113C 'openthread':26B,33B,110C,174C 'option':42B,123C 'out-of-bound':70B,159C 'overflow':7A 'overs':155C 'packet':6A,115C 'rcp':183C 'reboot':80B,203C 'requir':193C 'router':11A,35B,65B,112C,142C,148C,176C,181C,188C 'runtim':27B 'schedul':224C 'send':62B,144C 'stack':8A,52B,74B,86B,130C,166C,209C 'state':87B,210C 'thing':96C 'thread':28B,178C 'trust':36B,117C 'unaffect':191C 'user':197C 'version':216C,229C 'whose':154C 'without':185C 'write':75B,163C 'y':177C","nicknames":[],"mitigations":[],"who_affected":"Firmware built on ESP-IDF with CONFIG_OPENTHREAD_BORDER_ROUTER=y (off by default), in the affected versions listed. A host on the same infrastructure (backbone) link as the Border Router can send a crafted ICMPv6 Router Advertisement without authentication to crash or reboot it or corrupt adjacent stack memory. Thread end devices, routers and RCP firmware without the Border Router feature, and ESP-IDF 6.1+, can skip it.","tier":"B","verified":{"fix":{"at":"2026-11-04T19:32:05Z","by":"analyst","doc":"https://github.com/espressif/esp-idf/commit/4068c4e7d061b3e2d6096734509feadc14594e28","run_id":1696},"products":{"at":"2026-11-04T19:32:05Z","by":"analyst","doc":"https://github.com/espressif/esp-idf/commit/4068c4e7d061b3e2d6096734509feadc14594e28","run_id":1696},"workarounds":{"at":"2026-11-04T19:32:05Z","by":"analyst","doc":"https://github.com/espressif/esp-idf/commit/4068c4e7d061b3e2d6096734509feadc14594e28","run_id":1696},"how_to_check":{"at":"2026-11-04T19:32:05Z","by":"analyst","doc":"https://github.com/espressif/esp-idf/commit/4068c4e7d061b3e2d6096734509feadc14594e28","run_id":1696},"who_affected":{"at":"2026-11-04T19:32:05Z","by":"analyst","doc":"https://github.com/espressif/esp-idf/commit/4068c4e7d061b3e2d6096734509feadc14594e28","run_id":1696}},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":["espidf"],"ptokens":["esp","idf"],"labels":["embedded","espidf","high","iot","openthread","runtime","thread"],"campaign_type":null,"first_public_at":"2026-10-30T14:52:02+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","cvss_by":"security-advisories@github.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-113782","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-113782","severity":null,"published_at":"2026-11-04T19:17:18+00:00","modified_at":"2026-11-04T19:17:18+00:00","first_seen_at":"2026-11-04T19:28:48+00:00","fetched_at":"2026-11-04T19:28:48+00:00","note":null},{"source":"analyst","external_id":"CVE-2026-113782:1696","url":null,"severity":null,"published_at":"2026-11-04T19:32:05+00:00","modified_at":"2026-11-04T19:32:05+00:00","first_seen_at":"2026-11-04T19:32:05+00:00","fetched_at":"2026-11-04T19:32:05+00:00","note":"Read GHSA-c26h-gm53-qg83 (vendor). Affected 5.2.0-5.2.7, 5.3.0-5.3.5, 5.4.0-5.4.4, 5.5.0-5.5.4, 6.0.0-6.0.2; 6.1+ not affected; 5.1 and older EOL, no fix. 5.4.5 is not yet released (fix commit on release/v5.4 only). No exploitation or PoC seen."}],"documents":[{"id":69731,"url":"https://github.com/espressif/esp-idf/commit/4068c4e7d061b3e2d6096734509feadc14594e28","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":69732,"url":"https://github.com/espressif/esp-idf/commit/b6860b2db50406adf0aaebd75f2e9fe64cc805a9","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":69733,"url":"https://github.com/espressif/esp-idf/commit/c22480ba07fc1de454a63d42275c764d95c7bd9c","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":69734,"url":"https://github.com/espressif/esp-idf/commit/c828d0d709f1c46fa2b9e1ed3ce9d8dc4b29c42f","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":69735,"url":"https://github.com/espressif/esp-idf/commit/e18d27e480aec2b282898f4afc22b0f738ea7c04","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":69736,"url":"https://github.com/espressif/esp-idf/commit/f9bb1be59081ccef03a1b4b1fab9a225f28b1b61","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":69737,"url":"https://github.com/espressif/esp-idf/security/advisories/GHSA-c26h-gm53-qg83","title":"Vendor advisory: github.com","kind":"vendor","source":"nvd","publisher":"vendor","text":null,"published_at":"2026-10-30T14:52:02+00:00","relation":"advisory","confidence":null,"note":"Vendor advisory: github.com"}],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}