{"id":"CVE-2026-31403","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Hold net reference for the lifetime of /proc/fs/nfs/exports fd\n\nThe /proc/fs/nfs/exports proc entry is created at module init\nand persists for the module's lifeti…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Hold net reference for the lifetime of /proc/fs/nfs/exports fd\n\nThe /proc/fs/nfs/exports proc entry is created at module init\nand persists for the module's lifeti…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 3.9, < 5.10.253","linux_kernel >= 5.11, < 6.1.167","linux_kernel >= 6.2, < 6.6.130","linux_kernel >= 6.7, < 6.12.78","linux_kernel >= 6.13, < 6.18.20","linux_kernel >= 6.19, < 6.19.10","linux_kernel = 7.0"],"patched":["linux_kernel 6.19.10"],"published":"2026-04-03","updated":"2026-07-24","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-31403","references":[{"url":"https://git.kernel.org/stable/c/6a8d70e2ad6aad2c345a5048edcb8168036f97d6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/76740c28050dc6db2f5550f1325b00a11bbb3255","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c7f406fb341d6747634b8b1fa5461656e5e56076","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d1a19217995df9c7e4118f5a2820c5032fef2945","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/db4a9f99b12a7ee1c19d86c83a3b752c7effa6c6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e3d77f935639e6ae4b381c80464c31df998d61f4","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e7fcf179b82d3a3730fd8615da01b087cc654d0b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-082556.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00125,"epssPercentile":0.0255,"ingestedAt":"2026-07-25T22:05:04.311Z","slug":"CVE-2026-31403","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Hold net reference for the lifetime of /proc/fs/nfs/exports fd\n\nThe /proc/fs/nfs/exports proc entry is created at module init\nand persists for the module's lifetime. exports_proc_open()\ncaptures the caller's current network namespace and stores\nits svc_export_cache in seq->private, but takes no reference\non the namespace. If the namespace is subsequently torn down\n(e.g. container destruction after the opener does setns() to a\ndifferent namespace), nfsd_net_exit() calls nfsd_export_shutdown()\nwhich frees the cache. Subsequent reads on the still-open fd\ndereference the freed cache_detail, walking a freed hash table.\n\nHold a reference on the struct net for the lifetime of the open\nfile descriptor. This prevents nfsd_net_exit() from running --\nand thus prevents nfsd_export_shutdown() from freeing the cache\n-- while any exports fd is open. cache_detail already stores\nits net pointer (cd->net, set by cache_create_net()), so\nexports_release() can retrieve it without additional per-file\nstorage.\n\n## Affected\n\n- `linux_kernel >= 3.9, < 5.10.253`\n- `linux_kernel >= 5.11, < 6.1.167`\n- `linux_kernel >= 6.2, < 6.6.130`\n- `linux_kernel >= 6.7, < 6.12.78`\n- `linux_kernel >= 6.13, < 6.18.20`\n- `linux_kernel >= 6.19, < 6.19.10`\n- `linux_kernel = 7.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.19.10`","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}