{"id":"CVE-2026-87862","kind":"vulnerability","aliases":["CVE-2026-87862"],"related":[],"title":"curl: HSTS import drops longer-lived child entries, allowing plaintext HTTP requests","description":"Importing a `includeSubDomains` parent HSTS entry before a longer-lived child\nentry, silently drops the child. Consequently, when the parent expires, the\nchild's valid HSTS policy is lost, causing curl to issue unencrypted HTTP\nrequests rather than upgrading to HTTPS.","summary":"When curl imports an HSTS file where a parent domain with includeSubDomains comes before a longer-lived child entry, the child entry is silently discarded. After the parent expires, curl sends plain HTTP requests to the child host instead of upgrading to HTTPS.","severity":"medium","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["cli","curl","package","scripts"],"not_affected_if":["default-config","no-hsts-file"],"how_to_check":"- unknown","fix":"- unknown","status":"open","published_at":"2026-10-20T21:17:20+00:00","first_seen_at":"2026-10-23T21:57:21+00:00","triaged_at":"2026-10-25T05:04:28+00:00","updated_at":"2026-10-25T05:04:28+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-10-25T05:04:28Z","model":"claude-haiku-5-5","output":{"fix":"- unknown","reach":"network","title":"curl: HSTS import drops longer-lived child entries, allowing plaintext HTTP requests","impact":"medium","summary":"When curl imports an HSTS file where a parent domain with includeSubDomains comes before a longer-lived child entry, the child entry is silently discarded. After the parent expires, curl sends plain HTTP requests to the child host instead of upgrading to HTTPS.","category":"package","nicknames":[],"who_cares":["curl","cli","scripts"],"confidence":0.6,"needs_auth":"no","worst_case":"Requests to a subdomain fall back to plaintext HTTP, exposing traffic to interception.","analyst_note":"Find the affected and fixed curl versions from the NVD entry or curl's security advisory for CVE-2026-87862.","how_to_check":"- unknown","needs_analyst":true,"not_affected_if":["no-hsts-file","default-config"],"who_is_affected":"Teams that run curl with an HSTS cache file (--hsts) that is loaded from or built with imported entries, where a parent domain uses includeSubDomains and a subdomain has a longer max-age. Command-line or scripted curl that does not use an HSTS file is not affected by this import path. unknown for exact affected versions in the sources.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"medium"},"cost_usd":0.000573,"input_tokens":3311,"output_tokens":484,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':15A,18A '-87862':16A,19A 'allow':10A 'caus':98C 'child':8A,42B,45B,61B,79C,84C,91C 'cli':20B 'come':36B 'consequ':85C 'curl':1A,21B,25B,54B,99C 'cve':14A,17A 'discard':49B 'domain':33B 'drop':4A,82C 'entri':9A,43B,46B,73C,80C 'expir':53B,89C 'file':29B 'host':62B 'hsts':2A,28B,72C,94C 'http':12A,57B,103C 'https':67B,109C 'import':3A,26B,68C 'includesubdomain':35B,70C 'instead':63B 'issu':101C 'live':7A,41B,78C 'longer':6A,40B,77C 'longer-liv':5A,39B,76C 'lost':97C 'packag':22B 'parent':32B,52B,71C,88C 'plain':56B 'plaintext':11A 'polici':95C 'rather':105C 'request':13A,58B,104C 'script':23B 'send':55B 'silent':48B,81C 'unencrypt':102C 'upgrad':65B,107C 'valid':93C","nicknames":[],"mitigations":[],"who_affected":"Teams that run curl with an HSTS cache file (--hsts) that is loaded from or built with imported entries, where a parent domain uses includeSubDomains and a subdomain has a longer max-age. Command-line or scripted curl that does not use an HSTS file is not affected by this import path. unknown for exact affected versions in the sources.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-20T21:17:20+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-87862","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-87862","severity":null,"published_at":"2026-10-20T21:17:20+00:00","modified_at":"2026-10-22T17:21:57+00:00","first_seen_at":"2026-10-23T21:57:21+00:00","fetched_at":"2026-10-23T22:28:58+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"}