{"id":"CVE-2026-89540","title":"kernel: sunrpc: init gssp_lock before publishing proc entry (CVE-2026-89540)","summary":"A flaw was found in the Linux kernel's sunrpc component. A race condition exists where the `gssp_lock` mutex is not initialized before its associated `/proc/net/rpc/use-gss-proxy` entry is published. This allows a local attacker to trigger…","severity":"medium","cvss":4.7,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":["CWE-416","CWE-909"],"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 6","enterprise_linux 7","enterprise_linux 8","enterprise_linux 9","openshift_container_platform 4"],"published":"2026-09-11","updated":"2026-10-23","sourceUpdated":"2026-10-23T04:06:19+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89540.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89540.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89540"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532132"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89540"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89540"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89540.mbox"},{"url":"https://kernelcve.org/list/?q=CVE-2026-89540"},{"url":"https://git.kernel.org/stable/c/159a4fab7170badd6c4a553aef81cac079d6f4ee"},{"url":"https://git.kernel.org/stable/c/b3526ae3351968f6726bcbe25d8d09973ad79109"},{"url":"https://git.kernel.org/stable/c/7f5bcdc8da15077ebe846c2756a5a17741021410"},{"url":"https://git.kernel.org/stable/c/89c8e0733e8c46b7973503f15b1b31a8587d8030"},{"url":"https://git.kernel.org/stable/c/f15b87521168c2a92cb1931f532cba422f856f01"},{"url":"https://git.kernel.org/stable/c/edeefb111d6181a4aa278f415b005efe284b9489"},{"url":"https://git.kernel.org/stable/c/3f019571928b269feebcff59926ec13294215e0e"},{"url":"https://git.kernel.org/stable/c/5ce1ed6159731a41fdd0b03eedbed4e147036a5a"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00129,"epssPercentile":0.02546,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T19:23:23.496498Z"},"scores":{"vendor":7,"cna":7.8},"ingestedAt":"2026-09-14T15:23:07.452Z","slug":"CVE-2026-89540","body":"## Overview\n\nA flaw was found in the Linux kernel's sunrpc component. A race condition exists where the `gssp_lock` mutex is not initialized before its associated `/proc/net/rpc/use-gss-proxy` entry is published. This allows a local attacker to trigger a scenario where multiple writers can concurrently access the `set_gssp_clnt()` function, leading to a denial of service for the first writer's client and a resource leak.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-10-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89540.json)\n\n**kernel: sunrpc: init gssp_lock before publishing proc entry** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-10-23.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\nNo fix planned:\n\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\n## Remediation\n\nOut of support scope\n\nWorkarounds / mitigations:\n\n- Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.","depth":"sunlit","depthScore":26,"depthScoreParts":{"impact":25.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":228182,"id":"CVE-2026-89540","ts":1792758172558,"field":"cvss","old":"7.8","new":"4.7"},{"seq":228181,"id":"CVE-2026-89540","ts":1792758172558,"field":"severity","old":"high","new":"medium"},{"seq":223291,"id":"CVE-2026-89540","ts":1792180047384,"field":"cvss","old":"7","new":"7.8"},{"seq":205534,"id":"CVE-2026-89540","ts":1789576724345,"field":"cvss","old":"7.8","new":"7"},{"seq":197961,"id":"CVE-2026-89540","ts":1789384321160,"field":"cvss","old":"4.1","new":"7.8"},{"seq":197960,"id":"CVE-2026-89540","ts":1789384321160,"field":"severity","old":"medium","new":"high"},{"seq":183488,"id":"CVE-2026-89540","ts":1789356675576,"field":"cvss","old":"7.8","new":"4.1"},{"seq":183487,"id":"CVE-2026-89540","ts":1789356675576,"field":"severity","old":"high","new":"medium"},{"seq":153338,"id":"CVE-2026-89540","ts":1789285350105,"field":"cvss","old":null,"new":"7.8"},{"seq":153337,"id":"CVE-2026-89540","ts":1789285350105,"field":"severity","old":"none","new":"high"},{"seq":147714,"id":"CVE-2026-89540","ts":1789270211989,"field":"cvss","old":null,"new":"4.1"},{"seq":147713,"id":"CVE-2026-89540","ts":1789270211989,"field":"severity","old":"none","new":"medium"},{"seq":109478,"id":"CVE-2026-89540","ts":1789183732070,"field":"cvss","old":null,"new":"4.1"},{"seq":109477,"id":"CVE-2026-89540","ts":1789183732070,"field":"severity","old":"none","new":"medium"}]}