{"id":"CVE-2026-127081","kind":"vulnerability","aliases":["CVE-2026-127081"],"related":[],"title":"OpsTree BuildPiper: authenticated users can link stages to other projects' environments","description":"OpsTree BuildPiper before 2.7.0 contains an authorization bypass vulnerability that allows authenticated users to link pipeline stages to environments of other projects by supplying a foreign project_env_id. Attackers can submit another project's environment identifier to the POST /api/v1/pipeline/{pipeline_id}/stages/ endpoint, persisting cross-project associations that bypass project separation.","summary":"OpsTree BuildPiper before 2.7.0 lets a logged-in user attach pipeline stages to environments belonging to other projects by sending a foreign project_env_id to the stages endpoint. The cross-project links persist and break the separation between projects.","severity":"medium","cvss":5.3,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["buildpiper","ci-cd","other","self-hosted"],"not_affected_if":["single-project","trusted-users-only"],"how_to_check":"- Check the installed BuildPiper version; unknown if the sources give the exact command.\n- Review whether the pipeline stages API (POST /api/v1/pipeline/{pipeline_id}/stages/) is reachable by non-admin users.","fix":"- Move to BuildPiper `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":"2026-11-13T10:57:06+00:00","updated_at":"2026-11-13T10:57:06+00:00","category":"other","confidence":0.7,"triage":{"at":"2026-11-13T10:57:06Z","model":"claude-haiku-5-5","output":{"fix":"- Move to BuildPiper `2.7.0` or later.","reach":"network","title":"OpsTree BuildPiper: authenticated users can link stages to other projects' environments","impact":"low","summary":"OpsTree BuildPiper before 2.7.0 lets a logged-in user attach pipeline stages to environments belonging to other projects by sending a foreign project_env_id to the stages endpoint. The cross-project links persist and break the separation between projects.","audience":"businesses","category":"other","nicknames":[],"who_cares":["buildpiper","self-hosted","ci-cd"],"confidence":0.7,"fix_status":"available","needs_auth":"yes","worst_case":"Cross-project pipeline links that bypass project separation persist","analyst_note":"","how_to_check":"- Check the installed BuildPiper version; unknown if the sources give the exact command.\n- Review whether the pipeline stages API (POST /api/v1/pipeline/{pipeline_id}/stages/) is reachable by non-admin users.","plain_action":"","product_name":"","needs_analyst":false,"not_affected_if":["single-project","trusted-users-only"],"who_is_affected":"Teams that run a self-hosted BuildPiper instance with more than one project and let users other than administrators create pipeline stages. Single-project deployments or instances where only trusted staff have accounts are less exposed.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000723,"input_tokens":4615,"output_tokens":523,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-127081':14A,17A '-2026':13A,16A '/api/v1/pipeline':108C '/stages':111C '2.7.0':29B,71C 'allow':78C 'anoth':100C 'associ':117C 'attach':36B 'attack':97C 'authent':3A,79C 'author':74C 'belong':41B 'break':63B 'buildpip':2A,18B,27B,69C 'bypass':75C,119C 'cd':21B 'ci':20B 'ci-cd':19B 'contain':72C 'cross':58B,115C 'cross-project':57B,114C 'cve':12A,15A 'endpoint':55B,112C 'env':50B,95C 'environ':11A,40B,86C,103C 'foreign':48B,93C 'host':25B 'id':51B,96C,110C 'identifi':104C 'let':30B 'link':6A,60B,82C 'log':33B 'logged-in':32B 'opstre':1A,26B,68C 'persist':61B,113C 'pipelin':37B,83C,109C 'post':107C 'project':10A,44B,49B,59B,67B,89C,94C,101C,116C,120C 'self':24B 'self-host':23B 'send':46B 'separ':65B,121C 'stage':7A,38B,54B,84C 'submit':99C 'suppli':91C 'user':4A,35B,80C 'vulner':76C","nicknames":[],"mitigations":[],"who_affected":"Teams that run a self-hosted BuildPiper instance with more than one project and let users other than administrators create pipeline stages. Single-project deployments or instances where only trusted staff have accounts are less exposed.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["buildpiper","cicd","medium","other","selfhosted"],"campaign_type":null,"search_a":"'-127081':14A,17A '-2026':13A,16A 'authent':3A 'buildpip':2A 'cve':12A,15A 'environ':11A 'link':6A 'opstre':1A 'project':10A 'stage':7A 'user':4A","search_b":"'2.7.0':29B 'attach':36B 'belong':41B 'break':63B 'buildpip':18B,27B 'cd':21B 'ci':20B 'ci-cd':19B 'cross':58B 'cross-project':57B 'endpoint':55B 'env':50B 'environ':40B 'foreign':48B 'host':25B 'id':51B 'let':30B 'link':60B 'log':33B 'logged-in':32B 'opstre':26B 'persist':61B 'pipelin':37B 'project':44B,49B,59B,67B 'self':24B 'self-host':23B 'send':46B 'separ':65B 'stage':38B,54B 'user':35B","search_c":"'/api/v1/pipeline':108C '/stages':111C '2.7.0':71C 'allow':78C 'anoth':100C 'associ':117C 'attack':97C 'authent':79C 'author':74C 'buildpip':69C 'bypass':75C,119C 'contain':72C 'cross':115C 'cross-project':114C 'endpoint':112C 'env':95C 'environ':86C,103C 'foreign':93C 'id':96C,110C 'identifi':104C 'link':82C 'opstre':68C 'persist':113C 'pipelin':83C,109C 'post':107C 'project':89C,94C,101C,116C,120C 'separ':121C 'stage':84C 'submit':99C 'suppli':91C 'user':80C 'vulner':76C","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:N/VI:L/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-2026-127081","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-127081","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":145285,"url":"https://www.vulncheck.com/advisories/opstree-buildpiper-before-2.7.0-authorization-bypass-via-pipeline-stage-project-env-id","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. For higher limits or API access: sales@infrastack.ai"}