{"id":"CVE-2026-101608","kind":"vulnerability","aliases":["CVE-2026-101608"],"related":[],"title":"MySQL Server optimizer flaw lets low-privilege users 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 low 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 6.5 (Availability impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).","summary":"A flaw in the MySQL Server optimizer can be triggered by a low-privileged user over the network to cause a hang or repeatable crash. The impact is denial of service only, with no confidentiality or integrity loss stated.","severity":"medium","cvss":6.5,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["database","mysql","package","self-hosted"],"not_affected_if":["default-config"],"how_to_check":"- Run `SELECT VERSION();` on the MySQL server and compare against the affected ranges: 8.4.0 through 8.4.12, 9.7.0 through 9.7.3, 26.7.0 through 26.7.1, and MySQL Cluster 8.0.0 through 8.0.49.","fix":"- Upgrade MySQL Server 8.4.x to a release after `8.4.12`, 9.7.x to a release after `9.7.3`, and 26.7.x to a release after `26.7.1`.\n- Upgrade MySQL Cluster 8.0.x to a release after `8.0.49`, and MySQL Cluster 8.4.x and 9.7.x to the same fixed releases as MySQL Server.","status":"open","published_at":"2026-10-20T22:18:14+00:00","first_seen_at":"2026-10-23T21:57:22+00:00","triaged_at":"2026-10-25T03:55:10+00:00","updated_at":"2026-10-25T03:55:10+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-10-25T03:55:10Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade MySQL Server 8.4.x to a release after `8.4.12`, 9.7.x to a release after `9.7.3`, and 26.7.x to a release after `26.7.1`.\n- Upgrade MySQL Cluster 8.0.x to a release after `8.0.49`, and MySQL Cluster 8.4.x and 9.7.x to the same fixed releases as MySQL Server.","reach":"network","title":"MySQL Server optimizer flaw lets low-privilege users crash the database","impact":"low","summary":"A flaw in the MySQL Server optimizer can be triggered by a low-privileged user over the network to cause a hang or repeatable crash. The impact is denial of service only, with no confidentiality or integrity loss stated.","category":"package","nicknames":[],"who_cares":["mysql","database","self-hosted"],"confidence":0.7,"needs_auth":"yes","worst_case":"Attacker repeatedly crashes or hangs the database server, causing full denial of service.","analyst_note":"","how_to_check":"- Run `SELECT VERSION();` on the MySQL server and compare against the affected ranges: 8.4.0 through 8.4.12, 9.7.0 through 9.7.3, 26.7.0 through 26.7.1, and MySQL Cluster 8.0.0 through 8.0.49.","needs_analyst":false,"not_affected_if":["default-config"],"who_is_affected":"Teams running MySQL Server or MySQL Cluster in the listed version ranges are exposed, especially if database ports are reachable by users or applications that hold low-privileged accounts. Systems on patched or outside-listed versions, or with the database reachable only by fully trusted hosts, are less exposed.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000677,"input_tokens":3585,"output_tokens":636,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-101608':15A,18A '-2026':14A,17A '/av':159C '26.7.0':91C,102C '26.7.1':92C,103C '3.1':149C,158C '6.5':152C '8.0.0':95C '8.0.49':96C '8.4.0':87C,97C '8.4.12':88C,98C '9.7.0':89C,99C '9.7.3':90C,100C 'abil':132C 'access':113C 'affect':83C 'allow':107C 'attack':110C,124C 'avail':153C 'base':150C 'caus':45B,134C 'cluster':71C,94C,122C,147C 'complet':141C 'compon':76C 'compromis':118C 'confidenti':60B 'crash':10A,50B,140C 'cve':13A,16A 'cvss':148C,155C,157C 'databas':12A,19B 'denial':54B 'dos':142C 'easili':104C 'exploit':105C 'flaw':4A,26B 'frequent':138C 'h':167C 'hang':47B,136C 'host':24B 'impact':52B,154C 'integr':62B 'l/pr':161C 'l/ui':162C 'let':5A 'loss':63B 'low':7A,38B,108C 'low-privileg':6A,37B 'multipl':115C 'mysql':1A,20B,29B,68C,70C,75C,85C,93C,119C,121C,144C,146C 'n/a':166C 'n/ac':160C 'n/i':165C 'n/s':163C 'network':43B,112C 'optim':3A,31B,78C 'oracl':74C 'packag':21B 'privileg':8A,39B,109C 'product':72C 'protocol':116C 'repeat':49B,139C 'result':129C 'score':151C 'self':23B 'self-host':22B 'server':2A,30B,69C,77C,86C,120C,145C 'servic':56B 'state':64B 'success':123C 'support':79C 'trigger':34B 'u/c':164C 'unauthor':131C 'user':9A,40B 'vector':156C 'version':80C 'via':114C 'vulner':65C,106C,127C","nicknames":[],"mitigations":[],"who_affected":"Teams running MySQL Server or MySQL Cluster in the listed version ranges are exposed, especially if database ports are reachable by users or applications that hold low-privileged accounts. Systems on patched or outside-listed versions, or with the database reachable only by fully trusted hosts, are less exposed.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-20T22:18:14+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:L/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-2026-101608","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-101608","severity":null,"published_at":"2026-10-20T22:18:14+00:00","modified_at":"2026-10-21T18:43:53+00:00","first_seen_at":"2026-10-23T21:57:22+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"}