{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-89540 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-89540 is a high-severity vulnerability in Linux, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-89540 and fix it if it is affected.\n\nWhat it is: CVE-2026-89540 is a high-severity vulnerability in Linux, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-89540 in the wild and no public exploit code.\n\nAffected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-89540/ (Markdown: https://insights.sbomify.com/CVE-2026-89540/index.md)","id":"CVE-2026-89540","markdown":"https://insights.sbomify.com/CVE-2026-89540/index.md","name":"CVE-2026-89540","record":{"aliases":["AZL-100787","BELL-CVE-2026-89540","DEBIAN-CVE-2026-89540","GHSA-gwh2-5395-p8p6","UBUNTU-CVE-2026-89540"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service","data_read"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A race condition in the Linux kernel sunrpc module allows concurrent access to an uninitialized mutex, potentially causing crashes or memory leaks.","user_interaction":"not_required","vuln_class":"race_condition"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":7.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsunrpc: init gssp_lock before publishing proc entry\n\ncreate_use_gss_proxy_proc_entry() publishes /proc/net/rpc/use-gss-proxy\nvia proc_create_data() before init_gssp_clnt() runs mutex_init() on\nsn-\u003egssp_lock.  Once the dentry is linked under proc_subdir_lock it is\nimmediately reachable from userspace, so a write that lands in the\nwindow drives set_gssp_clnt() into mutex_lock() on a zero-initialized\nstruct mutex.\n\n    create_use_gss_proxy_proc_entry(net)\n      proc_create_data(\"use-gss-proxy\", ...)   /* dentry live */\n      init_gssp_clnt(sn)\n        mutex_init(\u0026sn-\u003egssp_lock)             /* too late */\n\n    write_gssp()\n      set_gssp_clnt(net)\n        mutex_lock(\u0026sn-\u003egssp_lock)             /* uninitialized */\n        gssp_rpc_create(...)\n        sn-\u003egssp_clnt = clnt\n        mutex_unlock(\u0026sn-\u003egssp_lock)\n\nThe window spans only the two statements between proc_create_data()\nreturning and init_gssp_clnt(), so a writer reaches it only if the\nregistering thread is preempted there while another task is already\nopening the freshly published file.  register_pernet_subsys() runs in\npreemptible context under pernet_ops_rwsem, so that preemption is\npossible, and the window widens on auth_rpcgss module load, when the\nproc entry is created for every live net namespace whose tasks are\nalready running.  A writer that wins the race locks a zero-filled\nstruct mutex.  On CONFIG_DEBUG_MUTEXES the missing magic value trips a\n\"lock used without init\" splat; on a production kernel the fast path\nacquires the lock via CMPXCHG(owner, 0, current).  In the latter case\na second writer that arrives before init_gssp_clnt() re-zeroes owner\ncan enter set_gssp_clnt() concurrently, shut down the first writer's\nclnt while it is still in use, and leak the loser's clnt.\n\nFix by initializing sn-\u003egssp_lock in sunrpc_init_net() so its lifetime\nmatches the sunrpc_net it lives in.  sn-\u003egssp_clnt is already NULL from\nthe kzalloc that backs net_generic storage, so the lazy helper is no\nlonger needed; drop init_gssp_clnt(), its prototype, and the call from\ncreate_use_gss_proxy_proc_entry().  sunrpc.ko is a build-time\ndependency of auth_rpcgss.ko, so sunrpc_init_net() has always run on\nevery netns before any auth_gss pernet init can publish the proc\nentry.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"sunrpc: init gssp_lock before publishing proc entry","id":"CVE-2026-89540","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"race_condition","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"SUNRPC: harden gss_unwrap_resp_priv length checks","id":"CVE-2026-89541"},"packages":[],"prev":{"headline":"SUNRPC: reject duplicate CREDS_VALUE options","id":"CVE-2026-89539"},"products":["Linux"],"published":"2026-09-11","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A race condition in the Linux kernel sunrpc module allows concurrent access to an uninitialized mutex, potentially causing crashes or memory leaks.","url":"https://insights.sbomify.com/CVE-2026-89540/"}