{"id":"CVE-2026-91381","kind":"vulnerability","aliases":["CVE-2026-91381"],"related":[],"title":"Oracle Java SE 2D: unauthenticated network flaw lets attacker change some data","description":"Vulnerability in the Oracle Java SE, Oracle GraalVM Enterprise Edition product of Oracle Java SE (component: 2D).  Supported versions that are affected are Oracle Java SE: 8u503 and  8u503-perf; Oracle GraalVM Enterprise Edition: 21.3.19.1.1. Difficult to exploit vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Oracle Java SE, Oracle GraalVM Enterprise Edition.  Successful attacks of this vulnerability can result in  unauthorized update, insert or delete access to some of Oracle Java SE, Oracle GraalVM Enterprise Edition accessible data. Note: This vulnerability can be exploited by using APIs in the specified Component, e.g., through a web service which supplies data to the APIs. This vulnerability also applies to Java deployments, typically in clients running sandboxed Java Web Start applications or sandboxed Java applets, that load and run untrusted code (e.g., code that comes from the internet) and rely on the Java sandbox for security. CVSS 3.1 Base Score 3.7 (Integrity impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N).","summary":"A flaw in the 2D component of Oracle Java SE 8u503 and GraalVM Enterprise 21.3.19.1.1 lets an unauthenticated remote attacker modify some accessible data. Exploitation is hard and can be reached through a web service that feeds data to the affected APIs, or through sandboxed Java applets and Web Start apps that run untrusted code.","severity":"low","cvss":3.7,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["graalvm","java","oracle-java","runtime","self-hosted"],"not_affected_if":["default-config","no-untrusted-input"],"how_to_check":"- Run `java -version` and compare against the affected build `8u503` (or `8u503-perf`)\n- For GraalVM Enterprise, check the version against `21.3.19.1.1`\n- Look for Java web services or applets that pass untrusted input to the 2D (java.awt, java.awt.image) APIs","fix":"- Move Oracle Java SE to the patched release listed in Oracle's April 2026 Critical Patch Update advisory (unknown exact version in sources)\n- Move Oracle GraalVM Enterprise to a patched release (unknown in sources)","status":"open","published_at":"2026-10-20T22:20:41+00:00","first_seen_at":"2026-10-23T21:57:26+00:00","triaged_at":"2026-10-25T04:43:46+00:00","updated_at":"2026-10-25T04:43:46+00:00","category":"runtime","confidence":0.6,"triage":{"at":"2026-10-25T04:43:46Z","model":"claude-haiku-5-5","output":{"fix":"- Move Oracle Java SE to the patched release listed in Oracle's April 2026 Critical Patch Update advisory (unknown exact version in sources)\n- Move Oracle GraalVM Enterprise to a patched release (unknown in sources)","reach":"network","title":"Oracle Java SE 2D: unauthenticated network flaw lets attacker change some data","impact":"low","summary":"A flaw in the 2D component of Oracle Java SE 8u503 and GraalVM Enterprise 21.3.19.1.1 lets an unauthenticated remote attacker modify some accessible data. Exploitation is hard and can be reached through a web service that feeds data to the affected APIs, or through sandboxed Java applets and Web Start apps that run untrusted code.","category":"runtime","nicknames":[],"who_cares":["java","oracle-java","graalvm","self-hosted"],"confidence":0.6,"needs_auth":"no","worst_case":"Attacker modifies some accessible Java application data","analyst_note":"Confirm the patched Java SE and GraalVM versions in Oracle's CPU advisory; the NVD entry gives no fix version.","how_to_check":"- Run `java -version` and compare against the affected build `8u503` (or `8u503-perf`)\n- For GraalVM Enterprise, check the version against `21.3.19.1.1`\n- Look for Java web services or applets that pass untrusted input to the 2D (java.awt, java.awt.image) APIs","needs_analyst":true,"not_affected_if":["default-config","no-untrusted-input"],"who_is_affected":"Teams running Oracle Java SE 8u503 or GraalVM Enterprise 21.3.19.1.1 on servers that accept network input processed by the 2D APIs, and client machines that run applets or Java Web Start apps from the internet. Systems on other Java versions, or without these APIs exposed to untrusted input, are less exposed.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"low"},"cost_usd":0.00072,"input_tokens":3684,"output_tokens":704,"severity_before":"low"},"analyst_status":null,"analyst_note":null,"search":"'-2026':14A,17A '-91381':15A,18A '/av':243C '21.3.19.1.1':42B,118C '2d':4A,32B,99C '3.1':233C,242C '3.7':236C '8u503':38B,109C,112C '8u503-perf':111C 'access':50B,128C,154C,165C 'affect':68B,104C 'allow':123C 'also':193C 'api':69B,175C,190C 'app':78B 'applet':74B,210C 'appli':194C 'applic':206C 'attack':9A,47B,125C,142C 'base':234C 'chang':10A 'client':200C 'code':82B,216C,218C 'come':220C 'compon':33B,98C,179C 'compromis':133C 'cve':13A,16A 'cvss':232C,239C,241C 'data':12A,51B,65B,166C,187C 'delet':153C 'deploy':197C 'difficult':119C 'e.g':180C,217C 'edit':92C,117C,140C,164C 'enterpris':41B,91C,116C,139C,163C 'exploit':52B,121C,172C 'feed':64B 'flaw':7A,29B 'graalvm':19B,40B,90C,115C,138C,162C 'h/pr':245C 'hard':54B 'host':27B 'impact':238C 'insert':151C 'integr':237C 'internet':223C 'java':2A,20B,23B,36B,73B,87C,96C,107C,135C,159C,196C,203C,209C,228C 'l/a':250C 'let':8A,43B 'load':212C 'modifi':48B 'multipl':130C 'n':251C 'n/ac':244C 'n/i':249C 'n/s':247C 'n/ui':246C 'network':6A,127C 'note':167C 'oracl':1A,22B,35B,86C,89C,95C,106C,114C,134C,137C,158C,161C 'oracle-java':21B 'perf':113C 'product':93C 'protocol':131C 'reach':58B 'reli':225C 'remot':46B 'result':147C 'run':80B,201C,214C 'runtim':24B 'sandbox':72B,202C,208C,229C 'score':235C 'se':3A,37B,88C,97C,108C,136C,160C 'secur':231C 'self':26B 'self-host':25B 'servic':62B,184C 'specifi':178C 'start':77B,205C 'success':141C 'suppli':186C 'support':100C 'typic':198C 'u/c':248C 'unauthent':5A,45B,124C 'unauthor':149C 'untrust':81B,215C 'updat':150C 'use':174C 'vector':240C 'version':101C 'via':129C 'vulner':83C,122C,145C,169C,192C 'web':61B,76B,183C,204C","nicknames":[],"mitigations":[],"who_affected":"Teams running Oracle Java SE 8u503 or GraalVM Enterprise 21.3.19.1.1 on servers that accept network input processed by the 2D APIs, and client machines that run applets or Java Web Start apps from the internet. Systems on other Java versions, or without these APIs exposed to untrusted input, are less exposed.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-20T22:20:41+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","cvss_by":"secalert_us@oracle.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-91381","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-91381","severity":null,"published_at":"2026-10-20T22:20:41+00:00","modified_at":"2026-10-21T18:45:11+00:00","first_seen_at":"2026-10-23T21:57:26+00:00","fetched_at":"2026-10-23T22:29:00+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"}