{"id":"CVE-2026-123205","kind":"vulnerability","aliases":["CVE-2026-123205"],"related":[],"title":"accel-ppp: remote heap overflow in log targets crashes the VPN daemon","description":"accel-ppp before 1.15.0 contains a heap buffer overflow vulnerability in the tcp, syslog and pgsql log targets that allows unauthenticated remote peers to overflow fixed heap buffers by producing log lines exceeding LOG_MAX_SIZE. Attackers within client-ip-range can send an L2TP Start-Control-Connection-Request with many string AVPs when verbose logging is enabled to corrupt heap memory and crash the daemon.","summary":"accel-ppp, a VPN server daemon for PPP and L2TP connections, has a heap buffer overflow in its tcp, syslog and pgsql log targets. An unauthenticated remote peer can corrupt heap memory by sending an L2TP Start-Control-Connection-Request with many string AVPs while verbose logging is enabled, which crashes the daemon.","severity":"high","cvss":8.3,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["accel-ppp","l2tp","linux","package","vpn-server"],"not_affected_if":["not-running-accel-ppp","verbose-logging-disabled"],"how_to_check":"- Check the installed accel-ppp version and see whether it is older than `1.15.0`.\n- Check the accel-ppp config for verbose logging and for the tcp, syslog or pgsql log targets.","fix":"- Move accel-ppp to `1.15.0` or later.","status":"open","published_at":"2026-11-05T19:17:19+00:00","first_seen_at":"2026-11-05T19:40:36+00:00","triaged_at":"2026-11-05T19:42:52+00:00","updated_at":"2026-11-05T19:42:52+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-11-05T19:42:52Z","model":"claude-haiku-5-5","output":{"fix":"- Move accel-ppp to `1.15.0` or later.","reach":"network","title":"accel-ppp: remote heap overflow in log targets crashes the VPN daemon","impact":"medium","summary":"accel-ppp, a VPN server daemon for PPP and L2TP connections, has a heap buffer overflow in its tcp, syslog and pgsql log targets. An unauthenticated remote peer can corrupt heap memory by sending an L2TP Start-Control-Connection-Request with many string AVPs while verbose logging is enabled, which crashes the daemon.","audience":"businesses","category":"package","nicknames":[],"who_cares":["accel-ppp","l2tp","vpn-server","linux"],"confidence":0.7,"fix_status":"available","needs_auth":"no","worst_case":"Remote peer crashes the accel-ppp daemon via heap corruption.","analyst_note":"Check the NVD and vendor release notes to confirm whether code execution is possible beyond the daemon crash, and whether the default config logs verbosely.","how_to_check":"- Check the installed accel-ppp version and see whether it is older than `1.15.0`.\n- Check the accel-ppp config for verbose logging and for the tcp, syslog or pgsql log targets.\n- unknown whether a public exploit exists or whether it leads to code execution.","plain_action":"","needs_analyst":true,"not_affected_if":["verbose-logging-disabled","not-running-accel-ppp"],"who_is_affected":"Servers running accel-ppp as an L2TP or PPP access concentrator are exposed, reachable from the client IP range. The sources say the issue needs verbose logging enabled to be triggered, so default-configured installs with verbose logging off are likely less exposed. Teams that do not run accel-ppp can skip it.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000764,"input_tokens":4343,"output_tokens":660,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-123205':16A,19A '-2026':15A,18A '1.15.0':88C 'accel':2A,21B,30B,85C 'accel-ppp':1A,20B,29B,84C 'allow':104C 'attack':121C 'avp':74B,139C 'buffer':44B,92C,112C 'client':124C 'client-ip-rang':123C 'connect':40B,69B,134C 'contain':89C 'control':68B,133C 'corrupt':59B,146C 'crash':10A,81B,150C 'cve':14A,17A 'daemon':13A,35B,83B,152C 'enabl':79B,144C 'exceed':117C 'fix':110C 'heap':5A,43B,60B,91C,111C,147C 'ip':125C 'l2tp':23B,39B,65B,130C 'line':116C 'linux':24B 'log':8A,52B,77B,101C,115C,118C,142C 'mani':72B,137C 'max':119C 'memori':61B,148C 'overflow':6A,45B,93C,109C 'packag':25B 'peer':57B,107C 'pgsql':51B,100C 'ppp':3A,22B,31B,37B,86C 'produc':114C 'rang':126C 'remot':4A,56B,106C 'request':70B,135C 'send':63B,128C 'server':28B,34B 'size':120C 'start':67B,132C 'start-control-connection-request':66B,131C 'string':73B,138C 'syslog':49B,98C 'target':9A,53B,102C 'tcp':48B,97C 'unauthent':55B,105C 'verbos':76B,141C 'vpn':12A,27B,33B 'vpn-server':26B 'vulner':94C 'within':122C","nicknames":[],"mitigations":[],"who_affected":"Servers running accel-ppp as an L2TP or PPP access concentrator are exposed, reachable from the client IP range. The sources say the issue needs verbose logging enabled to be triggered, so default-configured installs with verbose logging off are likely less exposed. Teams that do not run accel-ppp can skip it.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["accelppp","high","l2tp","linux","package","vpnserver"],"campaign_type":null,"first_public_at":"2026-11-05T19:17:19+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/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":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-123205","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-123205","severity":null,"published_at":"2026-11-05T19:17:19+00:00","modified_at":"2026-11-05T19:17:19+00:00","first_seen_at":"2026-11-05T19:40:36+00:00","fetched_at":"2026-11-05T19:40:36+00:00","note":null}],"documents":[{"id":79205,"url":"https://github.com/accel-ppp/accel-ppp/commit/58e399400c4ef4b71472ab7c2c71c54a677a05a8","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":79206,"url":"https://github.com/accel-ppp/accel-ppp/releases/tag/1.15.0","title":"Release notes: github.com","kind":"release","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Release notes: github.com"},{"id":79207,"url":"https://www.vulncheck.com/advisories/accel-ppp-before-1.15.0-heap-based-buffer-overflow-via-oversized-log-lines-in-log-tcp-log-syslog-log-pgsql","title":"Third-party advisory: www.vulncheck.com","kind":"advisory","source":"nvd","publisher":"research","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":"Third-party advisory: www.vulncheck.com"}],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}