{"id":"CVE-2026-101727","kind":"vulnerability","aliases":["CVE-2026-101727"],"related":[],"title":"MySQL Server replication flaw lets a privileged user crash the server","description":"Vulnerability in the MySQL Server, MySQL Cluster product of Oracle MySQL (component: Server: Replication).  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 replication component can be used by a high-privileged attacker over the network to 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":["databases","mysql","package","self-hosted"],"not_affected_if":["auth-required","unaffected-version"],"how_to_check":"- Run `SELECT VERSION();` in MySQL and compare against the affected ranges: MySQL Server 8.4.0 to 8.4.12, 9.7.0 to 9.7.3, 26.7.0 to 26.7.1; MySQL Cluster 8.0.0 to 8.0.49, 8.4.0 to 8.4.12, 9.7.0 to 9.7.3, 26.7.0 to 26.7.1.\n- Check whether replication is in use (source or replica roles) with `SHOW REPLICA STATUS;` or `SHOW BINARY LOG STATUS;`.","fix":"- Upgrade MySQL Server or MySQL Cluster to a release after the affected ranges listed above; the fixed version numbers are unknown from the sources.\n- Until patched, restrict which accounts hold high privileges and limit network access to the MySQL port.","status":"open","published_at":"2026-10-20T22:18:27+00:00","first_seen_at":"2026-10-23T21:57:23+00:00","triaged_at":"2026-10-25T04:31:27+00:00","updated_at":"2026-10-25T04:31:27+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-10-25T04:31:27Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade MySQL Server or MySQL Cluster to a release after the affected ranges listed above; the fixed version numbers are unknown from the sources.\n- Until patched, restrict which accounts hold high privileges and limit network access to the MySQL port.","reach":"network","title":"MySQL Server replication flaw lets a privileged user crash the server","impact":"low","summary":"A flaw in the MySQL Server replication component can be used by a high-privileged attacker over the network to 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","databases","self-hosted"],"confidence":0.7,"needs_auth":"yes","worst_case":"Repeatable crash or hang of the database server, causing denial of service","analyst_note":"","how_to_check":"- Run `SELECT VERSION();` in MySQL and compare against the affected ranges: MySQL Server 8.4.0 to 8.4.12, 9.7.0 to 9.7.3, 26.7.0 to 26.7.1; MySQL Cluster 8.0.0 to 8.0.49, 8.4.0 to 8.4.12, 9.7.0 to 9.7.3, 26.7.0 to 26.7.1.\n- Check whether replication is in use (source or replica roles) with `SHOW REPLICA STATUS;` or `SHOW BINARY LOG STATUS;`.","needs_analyst":false,"not_affected_if":["unaffected-version","auth-required"],"who_is_affected":"Teams running affected MySQL Server or MySQL Cluster releases, especially deployments using the replication component, where the attacker needs a high-privilege account reachable over the network. Systems on unaffected versions or without reachable high-privilege access can skip it.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000697,"input_tokens":3581,"output_tokens":677,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-101727':14A,17A '-2026':13A,16A '/av':162C '26.7.0':94C,105C '26.7.1':95C,106C '3.1':152C,161C '4.9':155C '8.0.0':98C '8.0.49':99C '8.4.0':90C,100C '8.4.12':91C,101C '9.7.0':92C,102C '9.7.3':93C,103C 'abil':135C 'access':116C 'affect':86C 'allow':110C 'attack':40B,113C,127C 'avail':156C 'base':153C 'caus':137C 'cluster':53B,74C,97C,125C,150C 'code':66B 'complet':144C 'compon':31B,79C 'compromis':121C 'crash':9A,48B,143C 'cve':12A,15A 'cvss':151C,158C,160C 'data':63B 'databas':18B 'denial':58B 'describ':56B 'dos':145C 'easili':107C 'execut':67B 'exploit':108C 'flaw':4A,25B 'frequent':141C 'h':170C 'h/ui':165C 'hang':45B,139C 'high':38B,111C 'high-privileg':37B 'host':23B 'impact':157C 'l/pr':164C 'let':5A 'multipl':118C 'mysql':1A,19B,28B,49B,52B,71C,73C,78C,88C,96C,122C,124C,147C,149C 'n/a':169C 'n/ac':163C 'n/i':168C 'n/s':166C 'network':43B,115C 'oracl':77C 'packag':20B 'privileg':7A,39B,112C 'product':75C 'protocol':119C 'read':64B 'repeat':47B,142C 'replic':3A,30B,81C 'result':132C 'score':154C 'self':22B 'self-host':21B 'server':2A,11A,29B,50B,72C,80C,89C,123C,148C 'servic':60B 'sourc':55B 'success':126C 'support':82C 'u/c':167C 'unauthor':134C 'use':34B 'user':8A 'vector':159C 'version':83C 'via':117C 'vulner':68C,109C,130C","nicknames":[],"mitigations":[],"who_affected":"Teams running affected MySQL Server or MySQL Cluster releases, especially deployments using the replication component, where the attacker needs a high-privilege account reachable over the network. Systems on unaffected versions or without reachable high-privilege access can skip it.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-20T22:18:27+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-2026-101727","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-101727","severity":null,"published_at":"2026-10-20T22:18:27+00:00","modified_at":"2026-10-22T18:17:16+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"}