{"id":"CVE-2026-127080","kind":"vulnerability","aliases":["CVE-2026-127080"],"related":[],"title":"OpsTree BuildPiper: deploy users can mount host root filesystem read-write","description":"OpsTree BuildPiper before 2.7.0 contains an improper authorization vulnerability that allows authenticated deploy users to define arbitrary Kubernetes hostPath volumes without allow-list or policy checks. Attackers can set the host path to / in the Define HostPath Volume configuration to mount the worker node root filesystem read-write, breaking container isolation and enabling node and cluster compromise.","summary":"BuildPiper before 2.7.0 lets authenticated deploy users define arbitrary Kubernetes hostPath volumes without allow-list or policy checks. An attacker can mount the worker node's root filesystem read-write, breaking container isolation and enabling node and cluster compromise.","severity":"critical","cvss":9.9,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["buildpiper","ci-cd","kubernetes","other"],"not_affected_if":["buildpiper-2.7.0-or-later"],"how_to_check":"- Check the installed BuildPiper version against the fixed release, `2.7.0`.\n- Review whether deploy users can set hostPath volumes in the Define HostPath Volume configuration.","fix":"- BuildPiper: move to `2.7.0` or later.","status":"open","published_at":"2026-11-13T10:18:04+00:00","first_seen_at":"2026-11-13T10:47:29+00:00","triaged_at":"2026-11-13T10:48:11+00:00","updated_at":"2026-11-13T10:48:11+00:00","category":"other","confidence":0.7,"triage":{"at":"2026-11-13T10:48:11Z","model":"claude-haiku-5-5","output":{"fix":"- BuildPiper: move to `2.7.0` or later.","reach":"network","title":"OpsTree BuildPiper: deploy users can mount host root filesystem read-write","impact":"high","summary":"BuildPiper before 2.7.0 lets authenticated deploy users define arbitrary Kubernetes hostPath volumes without allow-list or policy checks. An attacker can mount the worker node's root filesystem read-write, breaking container isolation and enabling node and cluster compromise.","audience":"businesses","category":"other","nicknames":[],"who_cares":["buildpiper","kubernetes","ci-cd"],"confidence":0.7,"fix_status":"available","needs_auth":"yes","worst_case":"Attacker mounts node root filesystem read-write, compromising node and cluster.","analyst_note":"Confirm the fixed version and any vendor advisory details at the vulncheck.com advisory linked in the sources.","how_to_check":"- Check the installed BuildPiper version against the fixed release, `2.7.0`.\n- Review whether deploy users can set hostPath volumes in the Define HostPath Volume configuration.\n- unknown for other checks; the sources do not give further steps.","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["buildpiper-2.7.0-or-later"],"who_is_affected":"BuildPiper installations before 2.7.0 where users with deploy permission can configure Kubernetes workloads. Deployments that are not BuildPiper, or that run only trusted deployers, are less exposed; the sources do not say more.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"critical"},"cost_usd":0.000751,"input_tokens":4615,"output_tokens":580,"severity_before":"critical"},"analyst_status":null,"analyst_note":null,"search":"'-127080':15A,18A '-2026':14A,17A '2.7.0':26B,68C 'allow':38B,75C,87C 'allow-list':37B,86C 'arbitrari':32B,81C 'attack':44B,92C 'authent':28B,76C 'author':72C 'break':56B,115C 'buildpip':2A,19B,24B,66C 'cd':22B 'check':42B,91C 'ci':21B 'ci-cd':20B 'cluster':63B,122C 'compromis':64B,123C 'configur':104C 'contain':57B,69C,116C 'cve':13A,16A 'defin':31B,80C,101C 'deploy':3A,29B,77C 'enabl':60B,119C 'filesystem':9A,52B,111C 'host':7A,96C 'hostpath':34B,83C,102C 'improp':71C 'isol':58B,117C 'kubernet':23B,33B,82C 'let':27B 'list':39B,88C 'mount':6A,46B,106C 'node':49B,61B,109C,120C 'opstre':1A,65C 'path':97C 'polici':41B,90C 'read':11A,54B,113C 'read-writ':10A,53B,112C 'root':8A,51B,110C 'set':94C 'user':4A,30B,78C 'volum':35B,84C,103C 'vulner':73C 'without':36B,85C 'worker':48B,108C 'write':12A,55B,114C","nicknames":[],"mitigations":[],"who_affected":"BuildPiper installations before 2.7.0 where users with deploy permission can configure Kubernetes workloads. Deployments that are not BuildPiper, or that run only trusted deployers, are less exposed; the sources do not say more.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["buildpiper","cicd","critical","kubernetes","other"],"campaign_type":null,"search_a":"'-127080':15A,18A '-2026':14A,17A 'buildpip':2A 'cve':13A,16A 'deploy':3A 'filesystem':9A 'host':7A 'mount':6A 'opstre':1A 'read':11A 'read-writ':10A 'root':8A 'user':4A 'write':12A","search_b":"'2.7.0':26B 'allow':38B 'allow-list':37B 'arbitrari':32B 'attack':44B 'authent':28B 'break':56B 'buildpip':19B,24B 'cd':22B 'check':42B 'ci':21B 'ci-cd':20B 'cluster':63B 'compromis':64B 'contain':57B 'defin':31B 'deploy':29B 'enabl':60B 'filesystem':52B 'hostpath':34B 'isol':58B 'kubernet':23B,33B 'let':27B 'list':39B 'mount':46B 'node':49B,61B 'polici':41B 'read':54B 'read-writ':53B 'root':51B 'user':30B 'volum':35B 'without':36B 'worker':48B 'write':55B","search_c":"'2.7.0':68C 'allow':75C,87C 'allow-list':86C 'arbitrari':81C 'attack':92C 'authent':76C 'author':72C 'break':115C 'buildpip':66C 'check':91C 'cluster':122C 'compromis':123C 'configur':104C 'contain':69C,116C 'defin':80C,101C 'deploy':77C 'enabl':119C 'filesystem':111C 'host':96C 'hostpath':83C,102C 'improp':71C 'isol':117C 'kubernet':82C 'list':88C 'mount':106C 'node':109C,120C 'opstre':65C 'path':97C 'polici':90C 'read':113C 'read-writ':112C 'root':110C 'set':94C 'user':78C 'volum':84C,103C 'vulner':73C 'without':85C 'worker':108C 'write':114C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-13T10:18:04+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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-2026-127080","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-127080","severity":null,"published_at":"2026-11-13T10:18:04+00:00","modified_at":"2026-11-13T10:18:04+00:00","first_seen_at":"2026-11-13T10:47:29+00:00","fetched_at":"2026-11-13T10:47:29+00:00","note":null}],"documents":[{"id":145284,"url":"https://www.vulncheck.com/advisories/opstree-buildpiper-before-2.7.0-container-escape-via-unrestricted-hostpath-volumes","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"}],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. 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