{"id":"CVE-2026-118336","kind":"vulnerability","aliases":["CVE-2026-118336"],"related":[],"title":"Chrome: Headless input validation flaw lets crafted HTML run code in sandbox","description":"Improper input validation in Headless in Google Chrome prior to 156.0.8078.73 allowed a remote attacker to potentially execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: High)","summary":"Improper input validation in Headless mode of Google Chrome before 156.0.8078.73 lets a remote attacker run arbitrary code inside the browser sandbox. The attack works through a crafted HTML page that a victim loads.","severity":"high","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browser-automation","chrome","headless-chrome","playwright","puppeteer","runtime","self-hosted"],"not_affected_if":["no-headless-chrome","trusted-content-only"],"how_to_check":"- Run `google-chrome --version` or `chromium --version` on machines and CI runners that use Chrome in headless mode, and compare against `156.0.8078.73`.\n- Check whether automation (Puppeteer, Playwright, Selenium) drives a bundled or system Chrome build that is older than `156.0.8078.73`.","fix":"- Update Google Chrome to `156.0.8078.73` or later.\n- Update the bundled Chromium in Puppeteer, Playwright or other headless tooling to a build that includes this fix.","status":"open","published_at":"2026-10-27T23:17:01+00:00","first_seen_at":"2026-10-27T23:29:43+00:00","triaged_at":"2026-10-27T23:31:47+00:00","updated_at":"2026-10-27T23:31:47+00:00","category":"runtime","confidence":0.6,"triage":{"at":"2026-10-27T23:31:47Z","model":"claude-haiku-5-5","output":{"fix":"- Update Google Chrome to `156.0.8078.73` or later.\n- Update the bundled Chromium in Puppeteer, Playwright or other headless tooling to a build that includes this fix.","reach":"internet","title":"Chrome: Headless input validation flaw lets crafted HTML run code in sandbox","impact":"high","summary":"Improper input validation in Headless mode of Google Chrome before 156.0.8078.73 lets a remote attacker run arbitrary code inside the browser sandbox. The attack works through a crafted HTML page that a victim loads.","category":"runtime","nicknames":[],"who_cares":["chrome","headless-chrome","browser-automation","puppeteer","playwright","self-hosted"],"confidence":0.6,"needs_auth":"no","worst_case":"Attacker runs code inside the browser sandbox via a crafted page","analyst_note":"Check the Chrome release notes for 156.0.8078.73 and the Chromium bug entry to confirm the headless-specific trigger and sandbox scope.","how_to_check":"- Run `google-chrome --version` or `chromium --version` on machines and CI runners that use Chrome in headless mode, and compare against `156.0.8078.73`.\n- Check whether automation (Puppeteer, Playwright, Selenium) drives a bundled or system Chrome build that is older than `156.0.8078.73`.","needs_analyst":true,"not_affected_if":["no-headless-chrome","trusted-content-only"],"who_is_affected":"Teams that run Chrome in headless mode, such as scrapers, test runners, PDF renderers or browser automation services, are exposed when they load untrusted HTML pages. Desktop users who never run headless Chrome are less exposed, but still should update. Systems that only render trusted, internal content have a lower risk.","user_interaction":"yes","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.00066,"input_tokens":3292,"output_tokens":662,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-118336':15A,18A '-2026':14A,17A '156.0.8078.73':42B,76C 'allow':77C 'arbitrari':48B,84C 'attack':46B,55B,80C 'autom':21B 'browser':20B,52B 'browser-autom':19B 'chrome':1A,22B,25B,40B,73C 'chromium':94C 'code':10A,49B,85C 'craft':7A,59B,91C 'cve':13A,16A 'execut':83C 'flaw':5A 'googl':39B,72C 'headless':2A,24B,36B,70C 'headless-chrom':23B 'high':97C 'host':31B 'html':8A,60B,92C 'improp':32B,66C 'input':3A,33B,67C 'insid':50B,86C 'let':6A,43B 'load':65B 'mode':37B 'page':61B,93C 'playwright':26B 'potenti':82C 'prior':74C 'puppet':27B 'remot':45B,79C 'run':9A,47B 'runtim':28B 'sandbox':12A,53B,88C 'secur':95C 'self':30B 'self-host':29B 'sever':96C 'valid':4A,34B,68C 'via':89C 'victim':64B 'work':56B","nicknames":[],"mitigations":[],"who_affected":"Teams that run Chrome in headless mode, such as scrapers, test runners, PDF renderers or browser automation services, are exposed when they load untrusted HTML pages. Desktop users who never run headless Chrome are less exposed, but still should update. Systems that only render trusted, internal content have a lower risk.","tier":"B","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T23:17:01+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-118336","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-118336","severity":null,"published_at":"2026-10-27T23:17:01+00:00","modified_at":"2026-10-27T23:17:01+00:00","first_seen_at":"2026-10-27T23:29:43+00:00","fetched_at":"2026-10-27T23:29:43+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}