{"id":"CVE-2026-109096","kind":"vulnerability","aliases":["CVE-2026-109096"],"related":[],"title":"X.Org X Server: negative return handling lets an authenticated client crash the server","description":"Incorrect handling of negative returns from ddQueryImageAttributes()  when processing XvPutImage requests in X.Org xwayland before 24.1.15 and X Server before 21.1.26 could be used by authenticated X clients to crash the X server.","summary":"A bug in how X.Org X Server and Xwayland handle a negative return from ddQueryImageAttributes() during XvPutImage requests. An authenticated X client can send a crafted request to crash the X server.","severity":"medium","cvss":5.5,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["infrastructure","linux","x.org","xserver","xwayland"],"not_affected_if":["no-x-server","trusted-clients-only"],"how_to_check":"- Run `Xorg -version` or `Xwayland -version` to read the installed version.\n- Check whether the installed X Server is earlier than `21.1.26` or Xwayland is earlier than `24.1.15`.","fix":"- Xwayland: move to `24.1.15` or later.\n- X Server: move to `21.1.26` or later.","status":"open","published_at":"2026-11-13T14:17:47+00:00","first_seen_at":"2026-11-13T15:19:48+00:00","triaged_at":"2026-11-13T15:21:32+00:00","updated_at":"2026-11-13T15:21:32+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-11-13T15:21:32Z","model":"claude-haiku-5-5","output":{"fix":"- Xwayland: move to `24.1.15` or later.\n- X Server: move to `21.1.26` or later.","reach":"local","title":"X.Org X Server: negative return handling lets an authenticated client crash the server","impact":"low","summary":"A bug in how X.Org X Server and Xwayland handle a negative return from ddQueryImageAttributes() during XvPutImage requests. An authenticated X client can send a crafted request to crash the X server.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["linux","x.org","xwayland","xserver"],"confidence":0.6,"fix_status":"available","needs_auth":"yes","worst_case":"X server crashes, disrupting the desktop session for all users","analyst_note":"","how_to_check":"- Run `Xorg -version` or `Xwayland -version` to read the installed version.\n- Check whether the installed X Server is earlier than `21.1.26` or Xwayland is earlier than `24.1.15`.","plain_action":"","product_name":"","needs_analyst":false,"not_affected_if":["no-x-server","trusted-clients-only"],"who_is_affected":"Systems running an X.Org X Server before 21.1.26 or Xwayland before 24.1.15 where clients can connect to the X server. The attacker must already hold an X client connection, so exposure is mostly on multi-user machines or hosts with untrusted local or networked X clients. Systems without an X server, or with X access limited to trusted clients, are less exposed.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000739,"input_tokens":4542,"output_tokens":570,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-109096':16A,19A '-2026':15A,18A '21.1.26':77C '24.1.15':72C 'authent':9A,44B,82C 'bug':26B 'client':10A,46B,84C 'could':78C 'craft':50B 'crash':11A,53B,86C 'cve':14A,17A 'ddqueryimageattribut':39B,63C 'handl':6A,34B,58C 'incorrect':57C 'infrastructur':20B 'let':7A 'linux':21B 'negat':4A,36B,60C 'process':65C 'request':42B,51B,67C 'return':5A,37B,61C 'send':48B 'server':3A,13A,31B,56B,75C,89C 'use':80C 'x':2A,30B,45B,55B,74C,83C,88C 'x.org':1A,22B,29B,69C 'xserver':23B 'xvputimag':41B,66C 'xwayland':24B,33B,70C","nicknames":[],"mitigations":[],"who_affected":"Systems running an X.Org X Server before 21.1.26 or Xwayland before 24.1.15 where clients can connect to the X server. The attacker must already hold an X client connection, so exposure is mostly on multi-user machines or hosts with untrusted local or networked X clients. Systems without an X server, or with X access limited to trusted clients, are less exposed.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["infrastructure","linux","medium","xorg","xserver","xwayland"],"campaign_type":null,"search_a":"'-109096':16A,19A '-2026':15A,18A 'authent':9A 'client':10A 'crash':11A 'cve':14A,17A 'handl':6A 'let':7A 'negat':4A 'return':5A 'server':3A,13A 'x':2A 'x.org':1A","search_b":"'authent':44B 'bug':26B 'client':46B 'craft':50B 'crash':53B 'ddqueryimageattribut':39B 'handl':34B 'infrastructur':20B 'linux':21B 'negat':36B 'request':42B,51B 'return':37B 'send':48B 'server':31B,56B 'x':30B,45B,55B 'x.org':22B,29B 'xserver':23B 'xvputimag':41B 'xwayland':24B,33B","search_c":"'21.1.26':77C '24.1.15':72C 'authent':82C 'client':84C 'could':78C 'crash':86C 'ddqueryimageattribut':63C 'handl':58C 'incorrect':57C 'negat':60C 'process':65C 'request':67C 'return':61C 'server':75C,89C 'use':80C 'x':74C,83C,88C 'x.org':69C 'xvputimag':66C 'xwayland':70C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-13T14:17:47+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvss_by":"meissner@suse.de","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-109096","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-109096","severity":null,"published_at":"2026-11-13T14:17:47+00:00","modified_at":"2026-11-13T14:17:47+00:00","first_seen_at":"2026-11-13T15:19:48+00:00","fetched_at":"2026-11-13T15:19:48+00:00","note":null}],"documents":[],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}