{"id":"CVE-2026-91664","kind":"vulnerability","aliases":["CVE-2026-91664"],"related":[],"title":"Oracle Essbase: unauthenticated network request can crash the server","description":"Vulnerability in Oracle Essbase (component: Security).   The supported version that is affected is 21.8.3.0.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via TCP to compromise Oracle Essbase.  Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Oracle Essbase. CVSS 3.1 Base Score 7.5 (Availability impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).","summary":"Oracle Essbase has a flaw in its Security component that lets an unauthenticated attacker over the network hang or repeatedly crash the service. The impact is availability only, with no code execution or data read in the sources.","severity":"high","cvss":7.5,"epss":0.00274,"exploited":false,"exploited_at":null,"products":[{"name":"oracle essbase","fixed":[],"affected":"= 21.8.3.0.0","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["oracle-essbase","self-hosted","vendor"],"not_affected_if":["unknown"],"how_to_check":"- Check the installed Essbase version against the affected release `21.8.3.0.0` in the Oracle advisory\n- unknown for further checks; the sources do not say how to confirm the Security component is reachable","fix":"- Apply the Oracle Critical Patch Update fix for Essbase; the fixed version is unknown in the sources\n- Restrict network access to the Essbase TCP port to trusted hosts until patched","status":"open","published_at":"2026-10-20T22:21:06+00:00","first_seen_at":"2026-10-23T21:57:27+00:00","triaged_at":"2026-10-25T03:17:06+00:00","updated_at":"2026-10-25T03:17:06+00:00","category":"vendor","confidence":0.6,"triage":{"at":"2026-10-25T03:17:06Z","model":"claude-haiku-5-5","output":{"fix":"- Apply the Oracle Critical Patch Update fix for Essbase; the fixed version is unknown in the sources\n- Restrict network access to the Essbase TCP port to trusted hosts until patched","reach":"network","title":"Oracle Essbase: unauthenticated network request can crash the server","impact":"low","summary":"Oracle Essbase has a flaw in its Security component that lets an unauthenticated attacker over the network hang or repeatedly crash the service. The impact is availability only, with no code execution or data read in the sources.","category":"vendor","nicknames":[],"who_cares":["oracle-essbase","self-hosted"],"confidence":0.6,"needs_auth":"no","worst_case":"Essbase service hangs or crashes repeatedly, causing denial of service","analyst_note":"Find the Oracle Critical Patch Update advisory for CVE-2026-91664 to confirm the fixed version and the affected TCP service.","how_to_check":"- Check the installed Essbase version against the affected release `21.8.3.0.0` in the Oracle advisory\n- unknown for further checks; the sources do not say how to confirm the Security component is reachable","needs_analyst":true,"not_affected_if":["unknown"],"who_is_affected":"Teams running Oracle Essbase version `21.8.3.0.0` that accept TCP connections from networks an attacker can reach. The sources do not say which Essbase configurations expose the vulnerable Security component by default. Deployments reachable only from a restricted internal network face less exposure.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.00063,"input_tokens":3491,"output_tokens":562,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-2026':11A,14A '-91664':12A,15A '/av':126C '21.8.3.0.0':76C '3.1':116C,125C '7.5':119C 'abil':101C 'access':85C 'affect':74C 'allow':80C 'attack':38B,82C,93C 'avail':51B,120C 'base':117C 'caus':103C 'code':55B 'complet':110C 'compon':33B,67C 'compromis':89C 'crash':7A,45B,109C 'cve':10A,13A 'cvss':115C,122C,124C 'data':58B 'dos':111C 'easili':77C 'essbas':2A,20B,26B,66C,91C,114C 'essbase':17A 'execut':56B 'exploit':78C 'flaw':29B 'frequent':107C 'h':134C 'hang':42B,105C 'host':23B 'impact':49B,121C 'l/pr':128C 'let':35B 'n/a':133C 'n/ac':127C 'n/i':132C 'n/s':130C 'n/ui':129C 'network':4A,41B,84C 'oracl':1A,19B,25B,65C,90C,113C 'oracle':16A 'oracle-essbas':18B 'read':59B 'repeat':44B,108C 'request':5A 'result':98C 'score':118C 'secur':32B,68C 'self':22B 'self-host':21B 'server':9A 'servic':47B 'sourc':62B 'success':92C 'support':70C 'tcp':87C 'u/c':131C 'unauthent':3A,37B,81C 'unauthor':100C 'vector':123C 'vendor':24B 'version':71C 'via':86C 'vulner':63C,79C,96C","nicknames":[],"mitigations":[],"who_affected":"Teams running Oracle Essbase version `21.8.3.0.0` that accept TCP connections from networks an attacker can reach. The sources do not say which Essbase configurations expose the vulnerable Security component by default. Deployments reachable only from a restricted internal network face less exposure.","tier":"B","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-20T22:21:06+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvss_by":"secalert_us@oracle.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-91664","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-91664","severity":null,"published_at":"2026-10-20T22:21:06+00:00","modified_at":"2026-10-23T17:15:47+00:00","first_seen_at":"2026-10-23T21:57:27+00:00","fetched_at":"2026-10-23T22:29:01+00:00","note":null},{"source":"epss","external_id":"CVE-2026-91664","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-91664","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-24T13:15:55+00:00","fetched_at":"2026-10-24T13:15:55+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"}