{"id":"CVE-2026-3583","kind":"vulnerability","aliases":["CVE-2026-3583"],"related":[],"title":"OAuth2 token introspection cache keeps revoked tokens after revocation request","description":"When the `allowed_scopes` configuration is enabled, the OAuth2 token introspection mechanism does not immediately invalidate a token in the cache after a revocation request. This results in a scenario where an access token that was introspected immediately before a revocation request may be returned again to the client after revocation, until the relevant cache entry is cleared.\n\nThe security consequence is that a revoked access token may be re-issued to the client during the cache lifetime. While the re-issued token is not treated as valid for API authorization, affected users may be unable to obtain a new valid access token until the cache is cleared, which can disrupt authentication flows.","summary":"When the allowed_scopes setting is enabled, the OAuth2 token introspection cache is not cleared right away after a token is revoked, so a revoked access token can be handed back to a client until the cache entry expires. The sources say the re-issued token is not accepted for API authorization, so the main effect is disrupted authentication, not unauthorized access.","severity":"low","cvss":3.1,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["authentication","oauth2","other"],"not_affected_if":["default-config"],"how_to_check":"- unknown","fix":"- unknown","status":"open","published_at":"2026-10-28T20:17:24+00:00","first_seen_at":"2026-10-28T20:35:10+00:00","triaged_at":"2026-10-28T20:36:20+00:00","updated_at":"2026-10-28T20:36:20+00:00","category":"other","confidence":0.4,"triage":{"at":"2026-10-28T20:36:20Z","model":"claude-haiku-5-5","output":{"fix":"- unknown","reach":"network","title":"OAuth2 token introspection cache keeps revoked tokens after revocation request","impact":"low","summary":"When the allowed_scopes setting is enabled, the OAuth2 token introspection cache is not cleared right away after a token is revoked, so a revoked access token can be handed back to a client until the cache entry expires. The sources say the re-issued token is not accepted for API authorization, so the main effect is disrupted authentication, not unauthorized access.","category":"other","nicknames":[],"who_cares":["oauth2","authentication"],"confidence":0.4,"needs_auth":"unknown","worst_case":"Revoked token reissued to clients, disrupting logins until cache clears","analyst_note":"Identify the affected product and versions from the NVD entry (https://nvd.nist.gov/vuln/detail/CVE-2026-3583) and find the vendor fix and cache-clearing guidance.","how_to_check":"- unknown","needs_analyst":true,"not_affected_if":["default-config"],"who_is_affected":"Systems running an OAuth2 server with the allowed_scopes configuration enabled and an introspection cache in use. Deployments without allowed_scopes or without introspection caching are not described as affected. The sources do not name the product or versions.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"unknown"},"cost_usd":0.000582,"input_tokens":3417,"output_tokens":480,"severity_before":"low"},"analyst_status":null,"analyst_note":null,"search":"'-2026':12A,15A '-3583':13A,16A 'accept':68B 'access':44B,81B,114C,147C,185C 'affect':175C 'allow':21B,84C 'api':70B,173C 'authent':17B,78B,195C 'author':71B,174C 'away':35B 'back':49B 'cach':4A,30B,55B,102C,136C,159C,189C 'clear':33B,139C,191C 'client':52B,130C,156C 'configur':86C 'consequ':142C 'cve':11A,14A 'disrupt':77B,194C 'effect':75B 'enabl':25B,88C 'entri':56B,137C 'expir':57B 'flow':196C 'hand':48B 'immedi':96C,119C 'introspect':3A,29B,92C,118C 'invalid':97C 'issu':64B,153C,165C 'keep':5A 'lifetim':160C 'main':74B 'may':124C,149C,177C 'mechan':93C 'new':183C 'oauth2':1A,18B,27B,90C 'obtain':181C 're':63B,152C,164C 're-issu':62B,151C,163C 'relev':135C 'request':10A,106C,123C 'result':108C 'return':126C 'revoc':9A,105C,122C,132C 'revok':6A,40B,43B,146C 'right':34B 'say':60B 'scenario':111C 'scope':22B,85C 'secur':141C 'set':23B 'sourc':59B 'token':2A,7A,28B,38B,45B,65B,91C,99C,115C,148C,166C,186C 'treat':169C 'unabl':179C 'unauthor':80B 'user':176C 'valid':171C,184C","nicknames":[],"mitigations":[],"who_affected":"Systems running an OAuth2 server with the allowed_scopes configuration enabled and an introspection cache in use. Deployments without allowed_scopes or without introspection caching are not described as affected. The sources do not name the product or versions.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-28T20:17:24+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L","cvss_by":"ed10eef1-636d-4fbe-9993-6890dfa878f8","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-3583","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-3583","severity":null,"published_at":"2026-10-28T20:17:24+00:00","modified_at":"2026-10-28T20:17:24+00:00","first_seen_at":"2026-10-28T20:35:10+00:00","fetched_at":"2026-10-28T20:35:10+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"}