{"cve":"CVE-2026-64059","nvd":{"published":"2026-07-19T16:17:46.407","modified":"2026-09-02T21:12:45.183","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfs: Fix folio->private handling in netfs_perform_write()\n\nUnder some circumstances, netfs_perform_write() doesn't correctly\nmanipulate folio->private between NULL, NETFS_FOLIO_COPY_TO_CACHE, pointing\nto a group and pointing to a netfs_folio struct, leading to potential\nmultiple attachments of private data with associated folio ref leaks and\nalso leaks of netfs_folio structs or netfs_group refs.\n\nFix this by consolidating the place at which a folio is marked uptodate in\none place and having that look at what's attached to folio->private and\ndecide how to clean it up and then set the new group.  Also, the content\nshouldn't be flushed if group is NULL, even if a group is specified in the\nnetfs_group parameter, as that would be the case for a new folio.  A\nfilesystem should always specify netfs_group or never specify netfs_group.\n\nThe Sashiko auto-review tool noted that it was theoretically possible that\nthe fpos >= ctx->zero_point section might leak if it modified a streaming\nwrite folio.  This is unlikely, but with a network filesystem, third party\nchanges can happen.  It also pointed out that __netfs_set_group() would\nleak if called multiple times on the same folio from the \"whole folio\nmodify section\".","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/0969ea8370bad0e4fb6131b6a7bed9e7ec522ac7","https://git.kernel.org/stable/c/551b5c71ee312ca7646ddb605231c1016e8cbb18","https://git.kernel.org/stable/c/7f040243c74d72b45b22246c7d9e621fbeab44ac","https://git.kernel.org/stable/c/ccde2ac757c713535b224233a296de40efe5212d"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:45:36.895656543+00:00"},"epss":{"cve":"CVE-2026-64059","score":0.00162,"percentile":0.05343,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}