{"id":"CVE-2026-121614","kind":"vulnerability","aliases":["CVE-2026-121614"],"related":[],"title":"Docker Sandboxes: repository Git config can run host programs outside isolation","description":"Docker Sandboxes versions 0.31.0 before 0.50.0 do not neutralize repository-controlled Git configuration when running certain host-side Git commands. An attacker who can modify a host repository's Git configuration, for example through a direct-mode sandbox with the repository mounted read-write, can configure core.fsmonitor or another Git setting that invokes an external program. Git can execute the program during a later clone-mode fetch or, starting in version 0.39.0, an sbx kit push initiated by the user. The program runs on the host with the invoking user's permissions, outside the sandbox's microVM isolation. The read-only host repository mount provided to a clone-mode sandbox does not itself allow that sandbox to modify the host repository's Git configuration. The issue is fixed in version 0.50.0.","summary":"Docker Sandboxes versions 0.31.0 before 0.50.0 fail to neutralize Git settings stored in a repository, such as core.fsmonitor, when running certain host-side Git commands. An attacker who can edit a host repository's Git configuration can make a later fetch or sbx kit push run an external program on the host with the user's permissions, outside the sandbox isolation.","severity":"high","cvss":7.1,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["developers","docker-sandboxes","git","other","sbx"],"not_affected_if":["not-using-docker-sandboxes","read-only-host-mount-clone-mode"],"how_to_check":"- Check the installed Docker Sandboxes (sbx) version and confirm whether it is below `0.50.0`.\n- Look at repositories mounted read-write into direct-mode sandboxes for changes to `.git/config` that set `core.fsmonitor` or other external-program Git settings.","fix":null,"status":"open","published_at":"2026-11-03T22:19:46+00:00","first_seen_at":"2026-11-03T23:15:09+00:00","triaged_at":"2026-11-03T23:16:11+00:00","updated_at":"2026-11-03T23:16:11+00:00","category":"other","confidence":0.7,"triage":{"at":"2026-11-03T23:16:11Z","model":"claude-haiku-5-5","output":{"fix":"- Docker Sandboxes: move to `0.50.0` or later.","reach":"local","title":"Docker Sandboxes: repository Git config can run host programs outside isolation","impact":"high","summary":"Docker Sandboxes versions 0.31.0 before 0.50.0 fail to neutralize Git settings stored in a repository, such as core.fsmonitor, when running certain host-side Git commands. An attacker who can edit a host repository's Git configuration can make a later fetch or sbx kit push run an external program on the host with the user's permissions, outside the sandbox isolation.","audience":"developers","category":"other","nicknames":[],"who_cares":["docker-sandboxes","sbx","git","developers"],"confidence":0.7,"fix_status":"available","needs_auth":"unknown","worst_case":"external program runs on the host with the user's permissions","analyst_note":"","how_to_check":"- Check the installed Docker Sandboxes (sbx) version and confirm whether it is below `0.50.0`.\n- Look at repositories mounted read-write into direct-mode sandboxes for changes to `.git/config` that set `core.fsmonitor` or other external-program Git settings.\n- unknown beyond this","plain_action":"","needs_analyst":false,"not_affected_if":["not-using-docker-sandboxes","read-only-host-mount-clone-mode"],"who_is_affected":"Teams that use Docker Sandboxes (sbx) with host repositories mounted read-write in direct mode, or that run sbx kit push from clone-mode sandboxes on version 0.39.0 or later. The sources say a read-only host repository mount for a clone-mode sandbox does not by itself let the sandbox alter the host Git configuration. Teams that do not use Docker Sandboxes can skip it.","user_interaction":"yes","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000757,"input_tokens":4307,"output_tokens":652,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-121614':14A,17A '-2026':13A,16A '0.31.0':28B,90C '0.39.0':163C '0.50.0':30B,92C,224C 'allow':207C 'anoth':139C 'attack':52B,110C 'certain':45B,103C 'clone':156C,201C 'clone-mod':155C,200C 'command':50B,108C 'config':5A 'configur':61B,100C,119C,136C,217C 'control':98C 'core.fsmonitor':42B,137C 'cve':12A,15A 'develop':18B 'direct':125C 'direct-mod':124C 'docker':1A,20B,25B,87C 'docker-sandbox':19B 'edit':55B 'exampl':121C 'execut':149C 'extern':73B,145C 'fail':31B 'fetch':66B,158C 'fix':221C 'git':4A,22B,34B,49B,60B,99C,107C,118C,140C,147C,216C 'host':8A,47B,57B,77B,105C,115C,177C,194C,213C 'host-sid':46B,104C 'initi':168C 'invok':143C,180C 'isol':11A,86B,189C 'issu':219C 'kit':69B,166C 'later':65B,154C 'make':63B 'microvm':188C 'mode':126C,157C,202C 'modifi':113C,211C 'mount':131C,196C 'neutral':33B,95C 'outsid':10A,83B,184C 'permiss':82B,183C 'program':9A,74B,146C,151C,173C 'provid':197C 'push':70B,167C 'read':133C,192C 'read-on':191C 'read-writ':132C 'repositori':3A,39B,58B,97C,116C,130C,195C,214C 'repository-control':96C 'run':7A,44B,71B,102C,174C 'sandbox':2A,21B,26B,85B,88C,127C,186C,203C,209C 'sbx':24B,68B,165C 'set':35B,141C 'side':48B,106C 'start':160C 'store':36B 'user':80B,171C,181C 'version':27B,89C,162C,223C 'write':134C","nicknames":[],"mitigations":[],"who_affected":"Teams that use Docker Sandboxes (sbx) with host repositories mounted read-write in direct mode, or that run sbx kit push from clone-mode sandboxes on version 0.39.0 or later. The sources say a read-only host repository mount for a clone-mode sandbox does not by itself let the sandbox alter the host Git configuration. Teams that do not use Docker Sandboxes can skip it.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"unknown","audience":"developers","plain_action":null,"pkeys":[],"ptokens":[],"labels":["developers","dockersandboxes","git","high","other","sbx"],"campaign_type":null,"first_public_at":"2026-11-03T22:19:46+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/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@docker.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-121614","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121614","severity":null,"published_at":"2026-11-03T22:19:46+00:00","modified_at":"2026-11-03T22:19:46+00:00","first_seen_at":"2026-11-03T23:15:09+00:00","fetched_at":"2026-11-03T23:15:09+00:00","note":null}],"documents":[{"id":61404,"url":"https://github.com/docker/sbx-releases/releases/tag/v0.50.0","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"}],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}