{"id":"CVE-2026-91255","kind":"vulnerability","aliases":["CVE-2026-91255"],"related":[],"title":"Oracle Solaris 11.4 kernel flaw lets unauthenticated remote hang or crash","description":"Vulnerability in the Oracle Solaris product of Oracle Systems (component: Kernel).   The supported version that is affected is 11.4. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Oracle Solaris.  Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Oracle Solaris. CVSS 3.1 Base Score 7.5 (Availability impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).","summary":"A flaw in the Oracle Solaris 11.4 kernel can be triggered over HTTP by an unauthenticated network attacker. The result is a hang or repeatable crash of the whole system, a denial of service with no code execution or data theft stated in the sources.","severity":"high","cvss":7.5,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["infrastructure","kernel","oracle","self-hosted","solaris"],"not_affected_if":["no-network-http-service","other-os"],"how_to_check":"- Run `uname -v` on the host and compare against the Oracle Solaris 11.4 patch level listed in the Oracle Critical Patch Update advisory (unknown from these sources)\n- Run `pkg info entire` to see the installed Solaris 11.4 release and SRU level","fix":"- Apply the Oracle Solaris 11.4 kernel patch from the Oracle Critical Patch Update advisory for the relevant quarter (exact patch id unknown from these sources)\n- Update with `pkg update` to the latest Solaris 11.4 SRU (exact version unknown from these sources)","status":"open","published_at":"2026-10-20T22:20:26+00:00","first_seen_at":"2026-10-23T21:57:26+00:00","triaged_at":"2026-10-25T03:18:38+00:00","updated_at":"2026-10-25T03:18:38+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-25T03:18:38Z","model":"claude-haiku-5-5","output":{"fix":"- Apply the Oracle Solaris 11.4 kernel patch from the Oracle Critical Patch Update advisory for the relevant quarter (exact patch id unknown from these sources)\n- Update with `pkg update` to the latest Solaris 11.4 SRU (exact version unknown from these sources)","reach":"internet","title":"Oracle Solaris 11.4 kernel flaw lets unauthenticated remote hang or crash","impact":"medium","summary":"A flaw in the Oracle Solaris 11.4 kernel can be triggered over HTTP by an unauthenticated network attacker. The result is a hang or repeatable crash of the whole system, a denial of service with no code execution or data theft stated in the sources.","category":"infrastructure","nicknames":[],"who_cares":["solaris","oracle","kernel","self-hosted"],"confidence":0.6,"needs_auth":"no","worst_case":"Remote attacker hangs or repeatedly crashes the Solaris host","analyst_note":"Find the exact Solaris 11.4 patch id and fixed SRU in the Oracle Critical Patch Update advisory for this CVE, and which HTTP service triggers it.","how_to_check":"- Run `uname -v` on the host and compare against the Oracle Solaris 11.4 patch level listed in the Oracle Critical Patch Update advisory (unknown from these sources)\n- Run `pkg info entire` to see the installed Solaris 11.4 release and SRU level","needs_analyst":true,"not_affected_if":["no-network-http-service","other-os"],"who_is_affected":"Systems running Oracle Solaris 11.4 that accept HTTP traffic from the network are the ones exposed, since the sources describe the attack as coming in over HTTP. Hosts with no network-facing HTTP service, or behind a firewall that blocks that traffic, are less exposed. The sources do not say which HTTP service or configuration triggers the flaw.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000698,"input_tokens":3442,"output_tokens":708,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-2026':13A,16A '-91255':14A,17A '/av':138C '11.4':3A,31B,88C '3.1':128C,137C '7.5':131C 'abil':113C 'access':97C 'affect':86C 'allow':92C 'attack':42B,94C,105C 'avail':132C 'base':129C 'caus':115C 'code':61B 'complet':122C 'compon':79C 'compromis':101C 'crash':11A,50B,121C 'cve':12A,15A 'cvss':127C,134C,136C 'data':64B 'denial':56B 'dos':123C 'easili':89C 'execut':62B 'exploit':90C 'flaw':5A,26B 'frequent':119C 'h':146C 'hang':9A,47B,117C 'host':23B 'http':37B,99C 'impact':133C 'infrastructur':18B 'kernel':4A,19B,32B,80C 'l/pr':140C 'let':6A 'n/a':145C 'n/ac':139C 'n/i':144C 'n/s':142C 'n/ui':141C 'network':41B,96C 'oracl':1A,20B,29B,73C,77C,102C,125C 'product':75C 'remot':8A 'repeat':49B,120C 'result':44B,110C 'score':130C 'self':22B 'self-host':21B 'servic':58B 'solari':2A,24B,30B,74C,103C,126C 'sourc':69B 'state':66B 'success':104C 'support':82C 'system':54B,78C 'theft':65B 'trigger':35B 'u/c':143C 'unauthent':7A,40B,93C 'unauthor':112C 'vector':135C 'version':83C 'via':98C 'vulner':70C,91C,108C 'whole':53B","nicknames":[],"mitigations":[],"who_affected":"Systems running Oracle Solaris 11.4 that accept HTTP traffic from the network are the ones exposed, since the sources describe the attack as coming in over HTTP. Hosts with no network-facing HTTP service, or behind a firewall that blocks that traffic, are less exposed. The sources do not say which HTTP service or configuration triggers the flaw.","tier":"B","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-20T22:20:26+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/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-2026-91255","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-91255","severity":null,"published_at":"2026-10-20T22:20:26+00:00","modified_at":"2026-10-22T19:18:03+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"}