{"id":"CVE-2026-123368","kind":"vulnerability","aliases":["CVE-2026-123368"],"related":[],"title":"compose-lint: symlinked .env leaks runner environment into scan output","description":"compose-lint is a Docker Compose security linter that identifies dangerous misconfigurations before deployment. From 0.22.0 until 0.31.0, compose-lint follows a sibling .env symbolic link outside the project without applying its normal containment check. From 0.28.0, the same gap also affects an include project_directory link outside the project. A pull request can reference a variable from the linked file, causing substitution to place runner file or process-environment data into finding messages written to logs, JSON, SARIF artifacts, and Code Scanning alerts. Reading /proc/self/environ can expose the remainder of the linter process environment because NUL-separated entries are treated as one value, although disclosure requires a workflow that processes untrusted changes with useful environment data and GitHub normally withholds secrets from fork pull requests. The pass or fail result is not changed. This issue is fixed in version 0.31.0.","summary":"compose-lint follows a sibling .env symlink that points outside the project without its containment check. A crafted pull request can make runner file or process environment data appear in findings, logs, and SARIF alerts.","severity":"low","cvss":2.3,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["ci","docker-compose","github-actions","package"],"not_affected_if":["no-untrusted-pull-requests","version-0.31.0-or-later"],"how_to_check":"- Check the installed version of compose-lint with `compose-lint --version` or the lockfile entry.\n- Look in CI workflows that run compose-lint on untrusted pull requests for environment-bearing setups.","fix":"- compose-lint: move to `0.31.0`.","status":"open","published_at":"2026-11-09T18:17:25+00:00","first_seen_at":"2026-11-09T18:27:55+00:00","triaged_at":"2026-11-09T18:29:28+00:00","updated_at":"2026-11-09T18:29:28+00:00","category":"package","confidence":0.8,"triage":{"at":"2026-11-09T18:29:28Z","model":"claude-haiku-5-5","output":{"fix":"- compose-lint: move to `0.31.0`.","reach":"network","title":"compose-lint: symlinked .env leaks runner environment into scan output","impact":"low","summary":"compose-lint follows a sibling .env symlink that points outside the project without its containment check. A crafted pull request can make runner file or process environment data appear in findings, logs, and SARIF alerts.","audience":"developers","category":"package","nicknames":[],"who_cares":["docker-compose","github-actions","ci"],"confidence":0.8,"fix_status":"available","needs_auth":"no","worst_case":"runner environment data appears in logs and scan alerts","analyst_note":"","how_to_check":"- Check the installed version of compose-lint with `compose-lint --version` or the lockfile entry.\n- Look in CI workflows that run compose-lint on untrusted pull requests for environment-bearing setups.","plain_action":"","product_name":"","needs_analyst":false,"not_affected_if":["version-0.31.0-or-later","no-untrusted-pull-requests"],"who_is_affected":"Teams running compose-lint in CI on Docker Compose projects, especially on pull requests from untrusted contributors, for versions from 0.22.0 through 0.30.x. Disclosure needs a workflow that processes untrusted changes and has useful environment data available; GitHub normally withholds secrets from fork pull requests. Pass or fail results are unchanged.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"yes","severity_if_unknown":"low"},"cost_usd":0.00074,"input_tokens":4783,"output_tokens":523,"severity_before":"low"},"analyst_status":null,"analyst_note":null,"search":"'-123368':14A,17A '-2026':13A,16A '/proc/self/environ':150C '0.22.0':78C '0.28.0':100C '0.31.0':80C,206C 'action':24B 'affect':105C 'alert':61B,148C 'also':104C 'although':170C 'appear':55B 'appli':94C 'artifact':144C 'caus':125C 'chang':178C,199C 'check':42B,98C 'ci':18B 'code':146C 'compos':2A,21B,27B,63C,68C,82C 'compose-lint':1A,26B,62C,81C 'contain':41B,97C 'craft':44B 'cve':12A,15A 'danger':73C 'data':54B,135C,182C 'deploy':76C 'directori':109C 'disclosur':171C 'docker':20B,67C 'docker-compos':19B 'entri':164C 'env':5A,32B,87C 'environ':8A,53B,134C,159C,181C 'expos':152C 'fail':195C 'file':50B,124C,130C 'find':57B,137C 'fix':203C 'follow':29B,84C 'fork':189C 'gap':103C 'github':23B,184C 'github-act':22B 'identifi':72C 'includ':107C 'issu':201C 'json':142C 'leak':6A 'link':89C,110C,123C 'lint':3A,28B,64C,83C 'linter':70C,157C 'log':58B,141C 'make':48B 'messag':138C 'misconfigur':74C 'normal':96C,185C 'nul':162C 'nul-separ':161C 'one':168C 'output':11A 'outsid':36B,90C,111C 'packag':25B 'pass':193C 'place':128C 'point':35B 'process':52B,133C,158C,176C 'process-environ':132C 'project':38B,92C,108C,113C 'pull':45B,115C,190C 'read':149C 'refer':118C 'remaind':154C 'request':46B,116C,191C 'requir':172C 'result':196C 'runner':7A,49B,129C 'sarif':60B,143C 'scan':10A,147C 'secret':187C 'secur':69C 'separ':163C 'sibl':31B,86C 'substitut':126C 'symbol':88C 'symlink':4A,33B 'treat':166C 'untrust':177C 'use':180C 'valu':169C 'variabl':120C 'version':205C 'withhold':186C 'without':39B,93C 'workflow':174C 'written':139C","nicknames":[],"mitigations":[],"who_affected":"Teams running compose-lint in CI on Docker Compose projects, especially on pull requests from untrusted contributors, for versions from 0.22.0 through 0.30.x. Disclosure needs a workflow that processes untrusted changes and has useful environment data available; GitHub normally withholds secrets from fork pull requests. Pass or fail results are unchanged.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":[],"ptokens":[],"labels":["ci","dockercompose","githubactions","low","package"],"campaign_type":null,"search_a":"'-123368':14A,17A '-2026':13A,16A 'compos':2A 'compose-lint':1A 'cve':12A,15A 'env':5A 'environ':8A 'leak':6A 'lint':3A 'output':11A 'runner':7A 'scan':10A 'symlink':4A","search_b":"'action':24B 'alert':61B 'appear':55B 'check':42B 'ci':18B 'compos':21B,27B 'compose-lint':26B 'contain':41B 'craft':44B 'data':54B 'docker':20B 'docker-compos':19B 'env':32B 'environ':53B 'file':50B 'find':57B 'follow':29B 'github':23B 'github-act':22B 'lint':28B 'log':58B 'make':48B 'outsid':36B 'packag':25B 'point':35B 'process':52B 'project':38B 'pull':45B 'request':46B 'runner':49B 'sarif':60B 'sibl':31B 'symlink':33B 'without':39B","search_c":"'/proc/self/environ':150C '0.22.0':78C '0.28.0':100C '0.31.0':80C,206C 'affect':105C 'alert':148C 'also':104C 'although':170C 'appli':94C 'artifact':144C 'caus':125C 'chang':178C,199C 'check':98C 'code':146C 'compos':63C,68C,82C 'compose-lint':62C,81C 'contain':97C 'danger':73C 'data':135C,182C 'deploy':76C 'directori':109C 'disclosur':171C 'docker':67C 'entri':164C 'env':87C 'environ':134C,159C,181C 'expos':152C 'fail':195C 'file':124C,130C 'find':137C 'fix':203C 'follow':84C 'fork':189C 'gap':103C 'github':184C 'identifi':72C 'includ':107C 'issu':201C 'json':142C 'link':89C,110C,123C 'lint':64C,83C 'linter':70C,157C 'log':141C 'messag':138C 'misconfigur':74C 'normal':96C,185C 'nul':162C 'nul-separ':161C 'one':168C 'outsid':90C,111C 'pass':193C 'place':128C 'process':133C,158C,176C 'process-environ':132C 'project':92C,108C,113C 'pull':115C,190C 'read':149C 'refer':118C 'remaind':154C 'request':116C,191C 'requir':172C 'result':196C 'runner':129C 'sarif':143C 'scan':147C 'secret':187C 'secur':69C 'separ':163C 'sibl':86C 'substitut':126C 'symbol':88C 'treat':166C 'untrust':177C 'use':180C 'valu':169C 'variabl':120C 'version':205C 'withhold':186C 'without':93C 'workflow':174C 'written':139C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-09-27T01:36:38+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:N/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":"security-advisories@github.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-123368","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-123368","severity":null,"published_at":"2026-11-09T18:17:25+00:00","modified_at":"2026-11-09T18:17:25+00:00","first_seen_at":"2026-11-09T18:27:55+00:00","fetched_at":"2026-11-09T18:27:55+00:00","note":null}],"documents":[{"id":108791,"url":"https://github.com/tmatens/compose-lint/commit/c43204ad4dab11d54e20574a52bc4e5835246ca5","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":108792,"url":"https://github.com/tmatens/compose-lint/releases/tag/v0.31.0","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":108793,"url":"https://github.com/tmatens/compose-lint/security/advisories/GHSA-6wcv-rj3c-mhv3","title":"Vendor advisory: github.com","kind":"vendor","source":"nvd","publisher":"vendor","text":null,"published_at":"2026-09-27T01:36:38+00:00","relation":"advisory","confidence":null,"note":"Vendor advisory: github.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"}