{"id":"CVE-2026-107608","kind":"vulnerability","aliases":["CVE-2026-107608"],"related":[],"title":"AWS CDK: symlinks injected during Docker asset bundling expose host files","description":"CVE-2026-107608: Improper link resolution in asset bundling output handling in aws-cdk-lib\n\n### CVE-2026-107608: Improper link resolution in asset bundling output handling in aws-cdk-lib\n\nBulletin ID: 2026-131-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 10/08/2026 12:30 PM PDT\n\nDescription:\n\nAWS CDK is an open source framework that allows customers to build cloud infrastructure using their favorite programming language (Python, Typescript, C#, Go). That infrastructure is then able to be deployed with AWS CDK command line commands to AWS CloudFormation. We identified CVE-2026-107608, which is an issue where Docker files could be configured to insert symlinked files into the output of the AWS CDK asset bundling process when it was invoked with a Docker file. When bundling an asset using AWS CDK with a docker file, prior to 2.267.0, it was possible for a docker file to insert a symlinked file or directory into the output of asset bundling without the symlink having been provided as input to the bundling process.\n\nImpacted versions: All aws-cdk-lib versions before 2.267.0\n\nResolution:\n\nThis issue has been addressed in aws-cdk-lib version 2.267.0. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.\n\nWorkarounds:\n\nIf you cannot immediately upgrade, you can reduce the possibility of streaming unexpected information by auditing all Docker bundling containers and their dependencies to confirm that no untrusted code executes inside the configured bundling environment.\n\nReferences:\n\n- CVE-2026-107608\n- GHSA-h6j4-qpp7-q28p\n\n Please email aws-security@amazon.com with any security questions or concerns.","summary":"In aws-cdk-lib before 2.267.0, a Dockerfile used for asset bundling could insert a symlinked file or directory into the bundling output without that symlink being declared as input. The symlink can point outside the bundle, so content from the build machine can be pulled into the deployed asset.","severity":"medium","cvss":6.8,"epss":0.00141,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["aws","aws-cdk","infrastructure-as-code","lab-disclosure","package","python","typescript"],"not_affected_if":["already-on-2.267.0-or-later","no-docker-bundling","trusted-dockerfiles-only"],"how_to_check":"- Run `npx cdk --version` or check `aws-cdk-lib` in `package.json` / `package-lock.json` against `2.267.0`\n- Search the project for Docker-based bundling (`bundling:` with `image` or a `dockerfile` in CDK constructs such as `lambda.Code.fromAsset` options) and review the Dockerfiles used\n- Check whether bundling runs untrusted or third-party Dockerfiles","fix":"- Upgrade `aws-cdk-lib` to `2.267.0` or later\n- Patch any forked or derivative CDK code, per the AWS bulletin\n- Until upgraded, audit all Docker bundling containers and their dependencies to confirm no untrusted code runs inside them","status":"open","published_at":"2026-10-08T20:17:34+00:00","first_seen_at":"2026-10-24T19:28:16+00:00","triaged_at":"2026-10-25T03:45:20+00:00","updated_at":"2026-10-25T12:38:49+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-10-25T03:45:20Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade `aws-cdk-lib` to `2.267.0` or later\n- Patch any forked or derivative CDK code, per the AWS bulletin\n- Until upgraded, audit all Docker bundling containers and their dependencies to confirm no untrusted code runs inside them","reach":"local","title":"AWS CDK: symlinks injected during Docker asset bundling expose host files","impact":"medium","summary":"In aws-cdk-lib before 2.267.0, a Dockerfile used for asset bundling could insert a symlinked file or directory into the bundling output without that symlink being declared as input. The symlink can point outside the bundle, so content from the build machine can be pulled into the deployed asset.","category":"package","nicknames":[],"who_cares":["aws-cdk","infrastructure-as-code","typescript","python","aws"],"confidence":0.7,"needs_auth":"unknown","worst_case":"symlinked host files get copied into deployed CDK assets","analyst_note":"","how_to_check":"- Run `npx cdk --version` or check `aws-cdk-lib` in `package.json` / `package-lock.json` against `2.267.0`\n- Search the project for Docker-based bundling (`bundling:` with `image` or a `dockerfile` in CDK constructs such as `lambda.Code.fromAsset` options) and review the Dockerfiles used\n- Check whether bundling runs untrusted or third-party Dockerfiles","needs_analyst":false,"not_affected_if":["already-on-2.267.0-or-later","no-docker-bundling","trusted-dockerfiles-only"],"who_is_affected":"Teams that use aws-cdk-lib before 2.267.0 with Docker-based asset bundling, where the Dockerfile or the image contents are not fully trusted. Projects that only use CDK without Docker bundling, or that build assets only from code they fully control, face much less risk. Teams already on 2.267.0 or later are not affected.","user_interaction":"unknown","needs_special_setup":"yes","severity_if_unknown":"medium"},"cost_usd":0.000748,"input_tokens":3919,"output_tokens":713,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-107608':14A,17A,85C,101C,179C,341C '-131':118C '-2026':13A,16A,84C,100C,178C,340C '10/08/2026':129C '12':130C '2.267.0':38B,225C,267C,280C '2026':117C '30':131C 'abl':162C 'address':273C 'allow':143C 'asset':7A,43B,82B,90C,106C,201C,215C,244C 'attent':126C 'audit':318C 'aw':1A,18B,20B,34B,96C,112C,119C,121C,135C,167C,173C,199C,217C,262C,276C 'aws-cdk':19B 'aws-cdk-lib':33B,95C,111C,261C,275C 'aws-security@amazon.com':349C 'build':74B,146C 'bulletin':115C 'bundl':8A,44B,54B,69B,91C,107C,202C,213C,245C,256C,321C,336C 'c':156C 'cannot':305C 'cdk':2A,21B,35B,97C,113C,136C,168C,200C,218C,263C,277C 'cloud':147C 'cloudform':174C 'code':25B,294C,331C 'command':169C,171C 'concern':355C 'configur':189C,335C 'confirm':327C 'contain':322C 'content':71B,122C 'could':45B,187C 'custom':144C 'cve':12A,15A,83C,99C,177C,339C 'date':128C 'declar':60B 'depend':325C 'deploy':81B,165C 'deriv':293C 'descript':134C 'directori':51B,239C 'disclosur':28B 'docker':6A,185C,210C,221C,231C,320C 'dockerfil':40B 'email':348C 'ensur':289C 'environ':337C 'execut':332C 'expos':9A 'favorit':151C 'file':11A,49B,186C,193C,211C,222C,232C,237C 'fix':301C 'fork':291C 'framework':141C 'ghsa':343C 'ghsa-h6j4-qpp7-q28p':342C 'go':157C 'h6j4':344C 'handl':93C,109C 'host':10A 'id':116C 'identifi':176C 'immedi':306C 'impact':258C 'import':124C 'improp':86C,102C 'incorpor':298C 'inform':316C 'infrastructur':23B,148C,159C 'infrastructure-as-cod':22B 'inject':4A 'input':62B,253C 'insert':46B,191C,234C 'insid':333C 'invok':207C 'issu':183C,270C 'lab':27B 'lab-disclosur':26B 'languag':153C 'latest':286C 'lib':36B,98C,114C,264C,278C 'line':170C 'link':87C,103C 'machin':75B 'new':300C 'open':139C 'output':55B,92C,108C,196C,242C 'outsid':67B 'packag':29B 'patch':296C 'pdt':133C 'pleas':347C 'pm':132C 'point':66B 'possibl':228C,312C 'prior':223C 'process':203C,257C 'program':152C 'provid':251C 'public':127C 'pull':78B 'python':30B,154C 'q28p':346C 'qpp7':345C 'question':353C 'recommend':282C 'reduc':310C 'refer':338C 'requir':125C 'resolut':88C,104C,268C 'scope':120C 'secur':352C 'sourc':140C 'stream':314C 'symlink':3A,48B,58B,64B,192C,236C,248C 'type':123C 'typescript':31B,155C 'unexpect':315C 'untrust':330C 'upgrad':283C,307C 'use':41B,149C,216C 'version':259C,265C,279C,287C 'without':56B,246C 'workaround':302C","nicknames":[],"mitigations":[{"kind":"workaround","scope":"aws-cdk-lib asset bundling with Docker","since":null,"covers":"Docker-based asset bundling in aws-cdk-lib before 2.267.0, by confirming that no untrusted code executes inside the bundling containers.","limits":"Does not fix the symlink insertion itself; the document states it only reduces the possibility of unexpected information being exposed.","source":"https://aws.amazon.com/security/security-bulletins/rss/2026-131-aws/","vendor":"Team","seen_at":"2026-10-25T10:14:43Z","sources":["https://aws.amazon.com/security/security-bulletins/rss/2026-131-aws/"],"confidence":0.7,"source_title":"CVE-2026-107608: Improper link resolution in asset bundling output handling in aws-cdk-lib","customer_action":"Audit all Docker bundling containers and their dependencies to confirm no untrusted code executes in the bundling environment, and upgrade to aws-cdk-lib 2.267.0."}],"who_affected":"Teams that use aws-cdk-lib before 2.267.0 with Docker-based asset bundling, where the Dockerfile or the image contents are not fully trusted. Projects that only use CDK without Docker bundling, or that build assets only from code they fully control, face much less risk. Teams already on 2.267.0 or later are not affected.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-08T20:17:34+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/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":"ff89ba41-3aa1-4d27-914a-91399e9639e5","poc_count":0,"sources":[{"source":"lab","external_id":"https://aws.amazon.com/security/security-bulletins/rss/2026-131-aws/#CVE-2026-107608","url":"https://aws.amazon.com/security/security-bulletins/rss/2026-131-aws/","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-24T19:28:16+00:00","fetched_at":"2026-10-25T10:15:36+00:00","note":"AWS: CVE-2026-107608: Improper link resolution in asset bundling output handling in aws-cdk-lib"},{"source":"nvd","external_id":"CVE-2026-107608","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-107608","severity":null,"published_at":"2026-10-08T20:17:34+00:00","modified_at":"2026-10-08T21:33:42+00:00","first_seen_at":"2026-10-24T20:15:27+00:00","fetched_at":"2026-10-24T20:15:27+00:00","note":null},{"source":"epss","external_id":"CVE-2026-107608","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-107608","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-25T12:38:49+00:00","fetched_at":"2026-10-25T12:38:49+00:00","note":null}],"documents":[{"id":2951,"url":"https://aws.amazon.com/security/security-bulletins/rss/2026-131-aws/","title":"AWS: CVE-2026-107608: Improper link resolution in asset bundling output handling in aws-cdk-lib","kind":"advisory","source":"lab","text":"CVE-2026-107608: Improper link resolution in asset bundling output handling in aws-cdk-lib\n\n### CVE-2026-107608: Improper link resolution in asset bundling output handling in aws-cdk-lib\n\nBulletin ID: 2026-131-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 10/08/2026 12:30 PM PDT\n\nDescription:\n\nAWS CDK is an open source framework that allows customers to build cloud infrastructure using their favorite programming language (Python, Typescript, C#, Go). That infrastructure is then able to be deployed with AWS CDK command line commands to AWS CloudFormation. We identified CVE-2026-107608, which is an issue where Docker files could be configured to insert symlinked files into the output of the AWS CDK asset bundling process when it was invoked with a Docker file. When bundling an asset using AWS CDK with a docker file, prior to 2.267.0, it was possible for a docker file to insert a symlinked file or directory into the output of asset bundling without the symlink having been provided as input to the bundling process.\n\nImpacted versions: All aws-cdk-lib versions before 2.267.0\n\nResolution:\n\nThis issue has been addressed in aws-cdk-lib version 2.267.0. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.\n\nWorkarounds:\n\nIf you cannot immediately upgrade, you can reduce the possibility of streaming unexpected information by auditing all Docker bundling containers and their dependencies to confirm that no untrusted code executes inside the configured bundling environment.\n\nReferences:\n\n- CVE-2026-107608\n- GHSA-h6j4-qpp7-q28p\n\n Please email aws-security@amazon.com with any security questions or concerns.","published_at":null,"relation":"advisory","confidence":null,"note":null}],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}