CVE-2026-64059netfs: Fix folio->private handling in netfs_perform_write()
- 5.5MediumCVSS base score
- 0.16%Exploitation in 30 daysEPSS · top 95% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: netfs: Fix folio->private handling in netfs_perform_write() Under some circumstances, netfs_perform_write() doesn't correctly manipulate folio->private between NULL, NETFS_FOLIO_COPY_TO_CACHE, pointing to a group and pointing to a netfs_folio struct, leading to potential multiple attachments of private data with associated folio ref leaks and also leaks of netfs_folio structs or netfs_group refs. Fix this by consolidating the place at which a folio is marked uptodate in one place and having that look at what's attached to folio->private and decide how to clean it up and then set the new group. Also, the content shouldn't be flushed if group is NULL, even if a group is specified in the netfs_group parameter, as that would be the case for a new folio. A filesystem should always specify netfs_group or never specify netfs_group. The Sashiko auto-review tool noted that it was theoretically possible that the fpos >= ctx->zero_point section might leak if it modified a streaming write folio. This is unlikely, but with a network filesystem, third party changes can happen. It also pointed out that __netfs_set_group() would leak if called multiple times on the same folio from the "whole folio modify section".
Timeline
ID reserved
By Linux
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Analyzed | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.16% · top 95% of all CVEs (15 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Affected products
- affected 8f52de0077ba3bf41e5d53d67a185700f41efce7 – < 7f040243c74d72b45b22246c7d9e621fbeab44ac
- affected 8f52de0077ba3bf41e5d53d67a185700f41efce7 – < 551b5c71ee312ca7646ddb605231c1016e8cbb18
- affected 8f52de0077ba3bf41e5d53d67a185700f41efce7 – < 0969ea8370bad0e4fb6131b6a7bed9e7ec522ac7
- affected 8f52de0077ba3bf41e5d53d67a185700f41efce7 – < ccde2ac757c713535b224233a296de40efe5212d
- affected 6.12
- unaffected < 6.12
- unaffected 6.12.92 – ≤ 6.12.*
- unaffected 6.18.34 – ≤ 6.18.*
- unaffected 7.0.11 – ≤ 7.0.*
- unaffected 7.1 – ≤ *
References
References4
- https://git.kernel.org/stable/c/7f040243c74d72b45b22246c7d9e621fbeab44ac (opens in a new tab)
- https://git.kernel.org/stable/c/551b5c71ee312ca7646ddb605231c1016e8cbb18 (opens in a new tab)
- https://git.kernel.org/stable/c/0969ea8370bad0e4fb6131b6a7bed9e7ec522ac7 (opens in a new tab)
- https://git.kernel.org/stable/c/ccde2ac757c713535b224233a296de40efe5212d (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-45632 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-64059)Record last updated .