{"id":"CVE-2026-101801","kind":"vulnerability","aliases":["CVE-2026-101801"],"related":[],"title":"MySQL Server: optimizer flaw lets a privileged user crash the database","description":"Vulnerability in the MySQL Server, MySQL Cluster product of Oracle MySQL (component: Server: Optimizer).  Supported versions that are affected are MySQL Server: 8.4.0-8.4.12, 9.7.0-9.7.3, 26.7.0-26.7.1; MySQL Cluster: 8.0.0-8.0.49, 8.4.0-8.4.12, 9.7.0-9.7.3 and  26.7.0-26.7.1. Easily exploitable vulnerability allows high privileged attacker with network access via multiple protocols to compromise MySQL Server, MySQL Cluster.  Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server, MySQL Cluster. CVSS 3.1 Base Score 4.9 (Availability impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).","summary":"A flaw in the MySQL Server optimizer lets a high-privileged user with network access hang or repeatedly crash MySQL Server and MySQL Cluster. The sources describe only a denial of service, with no code execution or data theft.","severity":"medium","cvss":4.9,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["database","mysql","mysql-cluster","package","self-hosted"],"not_affected_if":["no-privileged-accounts-exposed","unaffected-version"],"how_to_check":"- Run `SELECT VERSION();` on each MySQL Server and MySQL Cluster node and compare against the affected ranges: MySQL Server 8.4.0-8.4.12, 9.7.0-9.7.3, 26.7.0-26.7.1; MySQL Cluster 8.0.0-8.0.49, 8.4.0-8.4.12, 9.7.0-9.7.3, 26.7.0-26.7.1.","fix":"- Move MySQL Server and MySQL Cluster to a patched release listed in Oracle's Critical Patch Update for the affected branch; the fixed version numbers are unknown from the sources.","status":"open","published_at":"2026-10-20T22:18:35+00:00","first_seen_at":"2026-10-23T21:57:23+00:00","triaged_at":"2026-10-25T04:31:13+00:00","updated_at":"2026-10-25T04:31:13+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-10-25T04:31:13Z","model":"claude-haiku-5-5","output":{"fix":"- Move MySQL Server and MySQL Cluster to a patched release listed in Oracle's Critical Patch Update for the affected branch; the fixed version numbers are unknown from the sources.","reach":"network","title":"MySQL Server: optimizer flaw lets a privileged user crash the database","impact":"low","summary":"A flaw in the MySQL Server optimizer lets a high-privileged user with network access hang or repeatedly crash MySQL Server and MySQL Cluster. The sources describe only a denial of service, with no code execution or data theft.","category":"package","nicknames":[],"who_cares":["mysql","mysql-cluster","self-hosted","database"],"confidence":0.7,"needs_auth":"yes","worst_case":"Database server hangs or crashes repeatedly, causing denial of service.","analyst_note":"","how_to_check":"- Run `SELECT VERSION();` on each MySQL Server and MySQL Cluster node and compare against the affected ranges: MySQL Server 8.4.0-8.4.12, 9.7.0-9.7.3, 26.7.0-26.7.1; MySQL Cluster 8.0.0-8.0.49, 8.4.0-8.4.12, 9.7.0-9.7.3, 26.7.0-26.7.1.","needs_analyst":false,"not_affected_if":["unaffected-version","no-privileged-accounts-exposed"],"who_is_affected":"Deployments running the listed MySQL Server or MySQL Cluster versions are affected. Exposure is limited to accounts with high privileges, so teams that restrict admin-level database access face lower risk. Systems where only trusted administrators hold database accounts can plan the upgrade without urgency.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000673,"input_tokens":3585,"output_tokens":628,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-101801':14A,17A '-2026':13A,16A '/av':161C '26.7.0':93C,104C '26.7.1':94C,105C '3.1':151C,160C '4.9':154C '8.0.0':97C '8.0.49':98C '8.4.0':89C,99C '8.4.12':90C,100C '9.7.0':91C,101C '9.7.3':92C,102C 'abil':134C 'access':42B,115C 'affect':85C 'allow':109C 'attack':112C,126C 'avail':155C 'base':152C 'caus':136C 'cluster':22B,51B,73C,96C,124C,149C 'code':62B 'complet':143C 'compon':78C 'compromis':120C 'crash':9A,46B,142C 'cve':12A,15A 'cvss':150C,157C,159C 'data':65B 'databas':11A,18B 'denial':57B 'describ':54B 'dos':144C 'easili':106C 'execut':63B 'exploit':107C 'flaw':4A,28B 'frequent':140C 'h':169C 'h/ui':164C 'hang':43B,138C 'high':37B,110C 'high-privileg':36B 'host':26B 'impact':156C 'l/pr':163C 'let':5A,34B 'multipl':117C 'mysql':1A,19B,21B,31B,47B,50B,70C,72C,77C,87C,95C,121C,123C,146C,148C 'mysql-clust':20B 'n/a':168C 'n/ac':162C 'n/i':167C 'n/s':165C 'network':41B,114C 'optim':3A,33B,80C 'oracl':76C 'packag':23B 'privileg':7A,38B,111C 'product':74C 'protocol':118C 'repeat':45B,141C 'result':131C 'score':153C 'self':25B 'self-host':24B 'server':2A,32B,48B,71C,79C,88C,122C,147C 'servic':59B 'sourc':53B 'success':125C 'support':81C 'theft':66B 'u/c':166C 'unauthor':133C 'user':8A,39B 'vector':158C 'version':82C 'via':116C 'vulner':67C,108C,129C","nicknames":[],"mitigations":[],"who_affected":"Deployments running the listed MySQL Server or MySQL Cluster versions are affected. Exposure is limited to accounts with high privileges, so teams that restrict admin-level database access face lower risk. Systems where only trusted administrators hold database accounts can plan the upgrade without urgency.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-20T22:18:35+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:H/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-2026-101801","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-101801","severity":null,"published_at":"2026-10-20T22:18:35+00:00","modified_at":"2026-10-22T18:17:24+00:00","first_seen_at":"2026-10-23T21:57:23+00:00","fetched_at":"2026-10-23T22:28:59+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"}