{"id":"CVE-2026-101787","kind":"vulnerability","aliases":["CVE-2026-101787"],"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 highly privileged attacker over the network hang or repeatedly crash MySQL Server and MySQL Cluster. The sources describe only denial of service, with no data read or code execution.","severity":"medium","cvss":4.9,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["database","mysql","package","self-hosted"],"not_affected_if":["auth-required","managed-hosting"],"how_to_check":"- Run `SELECT VERSION();` on the MySQL server 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":null,"status":"open","published_at":"2026-10-20T22:18:34+00:00","first_seen_at":"2026-10-23T21:57:23+00:00","triaged_at":"2026-10-25T04:31:14+00:00","updated_at":"2026-10-25T04:31:14+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-10-25T04:31:14Z","model":"claude-haiku-5-5","output":{"fix":"unknown","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 highly privileged attacker over the network hang or repeatedly crash MySQL Server and MySQL Cluster. The sources describe only denial of service, with no data read or code execution.","category":"package","nicknames":[],"who_cares":["mysql","self-hosted","database"],"confidence":0.6,"needs_auth":"yes","worst_case":"Database server hangs or crashes repeatedly, causing denial of service","analyst_note":"Find the Oracle Critical Patch Update advisory for the fixed MySQL versions to fill in the fix field.","how_to_check":"- Run `SELECT VERSION();` on the MySQL server 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":true,"not_affected_if":["managed-hosting","auth-required"],"who_is_affected":"Teams running MySQL Server or MySQL Cluster in the affected version ranges. Exploiting it needs a highly privileged database account reachable over the network, so deployments that restrict accounts and network access face lower risk. The sources do not name a patched version.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.00064,"input_tokens":3585,"output_tokens":563,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-101787':14A,17A '-2026':13A,16A '/av':156C '26.7.0':88C,99C '26.7.1':89C,100C '3.1':146C,155C '4.9':149C '8.0.0':92C '8.0.49':93C '8.4.0':84C,94C '8.4.12':85C,95C '9.7.0':86C,96C '9.7.3':87C,97C 'abil':129C 'access':110C 'affect':80C 'allow':104C 'attack':35B,107C,121C 'avail':150C 'base':147C 'caus':131C 'cluster':47B,68C,91C,119C,144C 'code':60B 'complet':138C 'compon':73C 'compromis':115C 'crash':9A,42B,137C 'cve':12A,15A 'cvss':145C,152C,154C 'data':57B 'databas':11A,18B 'denial':52B 'describ':50B 'dos':139C 'easili':101C 'execut':61B 'exploit':102C 'flaw':4A,25B 'frequent':135C 'h':164C 'h/ui':159C 'hang':39B,133C 'high':33B,105C 'host':23B 'impact':151C 'l/pr':158C 'let':5A,31B 'multipl':112C 'mysql':1A,19B,28B,43B,46B,65C,67C,72C,82C,90C,116C,118C,141C,143C 'n/a':163C 'n/ac':157C 'n/i':162C 'n/s':160C 'network':38B,109C 'optim':3A,30B,75C 'oracl':71C 'packag':20B 'privileg':7A,34B,106C 'product':69C 'protocol':113C 'read':58B 'repeat':41B,136C 'result':126C 'score':148C 'self':22B 'self-host':21B 'server':2A,29B,44B,66C,74C,83C,117C,142C 'servic':54B 'sourc':49B 'success':120C 'support':76C 'u/c':161C 'unauthor':128C 'user':8A 'vector':153C 'version':77C 'via':111C 'vulner':62C,103C,124C","nicknames":[],"mitigations":[],"who_affected":"Teams running MySQL Server or MySQL Cluster in the affected version ranges. Exploiting it needs a highly privileged database account reachable over the network, so deployments that restrict accounts and network access face lower risk. The sources do not name a patched version.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-20T22:18:34+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-2026-101787","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-101787","severity":null,"published_at":"2026-10-20T22:18:34+00:00","modified_at":"2026-10-22T18:17:23+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"}