{"id":"CVE-2026-87861","kind":"vulnerability","aliases":["CVE-2026-87861"],"related":[],"title":"HTTP client: requests can reuse a connection authenticated for another origin","description":"When using ambient user credentials, an HTTP request directed to one origin\nmay be dispatched over a connection previously authenticated via Negotiate for\na different origin, leaving the request's intended credentials unused.","summary":"When ambient user credentials are in use, an HTTP request aimed at one origin can be sent over a connection already authenticated via Negotiate for a different origin. The request then goes out without the credentials it was meant to carry, and the sources do not say which library or product is affected.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["http-client","negotiate-auth","package"],"not_affected_if":[],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-10-20T21:17:20+00:00","first_seen_at":"2026-10-23T21:57:21+00:00","triaged_at":"2026-10-25T05:04:30+00:00","updated_at":"2026-10-25T05:04:30+00:00","category":"package","confidence":0.3,"triage":{"at":"2026-10-25T05:04:30Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"unknown","title":"HTTP client: requests can reuse a connection authenticated for another origin","impact":"low","summary":"When ambient user credentials are in use, an HTTP request aimed at one origin can be sent over a connection already authenticated via Negotiate for a different origin. The request then goes out without the credentials it was meant to carry, and the sources do not say which library or product is affected.","category":"package","nicknames":[],"who_cares":["negotiate-auth","http-client"],"confidence":0.3,"needs_auth":"unknown","worst_case":"unknown","analyst_note":"Identify the affected library and versions from the NVD entry at https://nvd.nist.gov/vuln/detail/CVE-2026-87861 and its CNA advisory.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":[],"who_is_affected":"unknown","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000502,"input_tokens":3271,"output_tokens":350,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':13A,16A '-87861':14A,17A 'affect':77B 'aim':35B 'alreadi':45B 'ambient':26B,80C 'anoth':10A 'auth':23B 'authent':8A,46B,97C 'carri':65B 'client':2A,20B 'connect':7A,44B,95C 'credenti':28B,60B,82C,109C 'cve':12A,15A 'differ':51B,102C 'direct':86C 'dispatch':92C 'goe':56B 'http':1A,19B,33B,84C 'http-client':18B 'intend':108C 'leav':104C 'librari':73B 'may':90C 'meant':63B 'negoti':22B,48B,99C 'negotiate-auth':21B 'one':37B,88C 'origin':11A,38B,52B,89C,103C 'packag':24B 'previous':96C 'product':75B 'request':3A,34B,54B,85C,106C 'reus':5A 'say':71B 'sent':41B 'sourc':68B 'unus':110C 'use':31B,79C 'user':27B,81C 'via':47B,98C 'without':58B","nicknames":[],"mitigations":[],"who_affected":null,"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-2026-87861","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-87861","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"}