{"id":"CVE-2026-57188","kind":"vulnerability","aliases":["CVE-2026-57188"],"related":[],"title":"Asterisk: XMPP namespace handling lets an authenticated peer overflow the stack","description":"Asterisk is an open source private branch exchange and telephony toolkit. Prior to Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3, an authenticated attacker may cause a stack buffer overflow in `res_xmpp` `XMPP namespace prefix` handling using carefully crafted packets. The `res_xmpp` module must be loaded, an XMPP connection must be configured in `xmpp.conf`, and the attacker must have an XMPP account on the same or a federated server. This issue is fixed in Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3.","summary":"Asterisk's res_xmpp module mishandles XMPP namespace prefixes, allowing a stack buffer overflow when crafted packets are processed. An attacker with an XMPP account on the same or a federated server can trigger it, and the sources do not state whether code execution is achievable.","severity":"high","cvss":7.1,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["asterisk","package","self-hosted","telephony","voip"],"not_affected_if":["res-xmpp-not-loaded","xmpp-not-configured"],"how_to_check":"- Run `asterisk -V` and compare against the fixed versions.\n- Check `xmpp.conf` for a configured XMPP connection and confirm `res_xmpp` is loaded with `asterisk -rx \"module show like res_xmpp\"`.\n- Only systems with both of these are exposed.","fix":"- Upgrade Asterisk to `20.20.1`, `21.12.3`, `22.10.1` or `23.4.1`.\n- Upgrade Certified Asterisk to `20.7-cert11` or `22.8-cert3`.\n- Alternatively, unload `res_xmpp` or remove the XMPP connection from `xmpp.conf` until patched.","status":"open","published_at":"2026-10-27T18:17:37+00:00","first_seen_at":"2026-10-27T18:33:00+00:00","triaged_at":"2026-10-27T18:34:41+00:00","updated_at":"2026-10-27T18:34:41+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-10-27T18:34:41Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade Asterisk to `20.20.1`, `21.12.3`, `22.10.1` or `23.4.1`.\n- Upgrade Certified Asterisk to `20.7-cert11` or `22.8-cert3`.\n- Alternatively, unload `res_xmpp` or remove the XMPP connection from `xmpp.conf` until patched.","reach":"network","title":"Asterisk: XMPP namespace handling lets an authenticated peer overflow the stack","impact":"high","summary":"Asterisk's res_xmpp module mishandles XMPP namespace prefixes, allowing a stack buffer overflow when crafted packets are processed. An attacker with an XMPP account on the same or a federated server can trigger it, and the sources do not state whether code execution is achievable.","category":"package","nicknames":[],"who_cares":["asterisk","telephony","voip","self-hosted"],"confidence":0.7,"needs_auth":"yes","worst_case":"Authenticated XMPP peer overflows stack; code execution not confirmed by sources.","analyst_note":"Check the Asterisk security advisory for whether the stack overflow allows code execution and for exact affected version ranges.","how_to_check":"- Run `asterisk -V` and compare against the fixed versions.\n- Check `xmpp.conf` for a configured XMPP connection and confirm `res_xmpp` is loaded with `asterisk -rx \"module show like res_xmpp\"`.\n- Only systems with both of these are exposed.","needs_analyst":true,"not_affected_if":["xmpp-not-configured","res-xmpp-not-loaded"],"who_is_affected":"Only Asterisk deployments that load the res_xmpp module and have an XMPP connection configured in xmpp.conf are exposed. The attacker must hold an XMPP account on the same server or a federated one, so systems without XMPP can skip it.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000693,"input_tokens":3471,"output_tokens":691,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-2026':13A,16A '-57188':14A,17A '20.20.1':85C,152C '20.7':92C,159C '21.12.3':86C,153C '22.10.1':87C,154C '22.8':94C,161C '23.4.1':88C,155C 'account':49B,138C 'achiev':70B 'allow':34B 'asterisk':1A,18B,25B,71C,84C,91C,151C,158C 'attack':45B,98C,133C 'authent':7A,97C 'branch':77C 'buffer':37B,103C 'care':113C 'caus':100C 'cert11':93C,160C 'cert3':95C,162C 'certifi':90C,157C 'code':67B 'configur':128C 'connect':125C 'craft':40B,114C 'cve':12A,15A 'exchang':78C 'execut':68B 'feder':55B,144C 'fix':149C 'handl':4A,111C 'host':22B 'issu':147C 'let':5A 'load':122C 'may':99C 'mishandl':30B 'modul':29B,119C 'must':120C,126C,134C 'namespac':3A,32B,109C 'open':74C 'overflow':9A,38B,104C 'packag':19B 'packet':41B,115C 'peer':8A 'prefix':33B,110C 'prior':82C 'privat':76C 'process':43B 'res':27B,106C,117C 'self':21B 'self-host':20B 'server':56B,145C 'sourc':62B,75C 'stack':11A,36B,102C 'state':65B 'telephoni':23B,80C 'toolkit':81C 'trigger':58B 'use':112C 'voip':24B 'whether':66B 'xmpp':2A,28B,31B,48B,107C,108C,118C,124C,137C 'xmpp.conf':130C","nicknames":[],"mitigations":[],"who_affected":"Only Asterisk deployments that load the res_xmpp module and have an XMPP connection configured in xmpp.conf are exposed. The attacker must hold an XMPP account on the same server or a federated one, so systems without XMPP can skip it.","tier":"B","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T18:17:37+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/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":"security-advisories@github.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-57188","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-57188","severity":null,"published_at":"2026-10-27T18:17:37+00:00","modified_at":"2026-10-27T18:17:37+00:00","first_seen_at":"2026-10-27T18:33:00+00:00","fetched_at":"2026-10-27T18:33:00+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"}