CVE-2026-68086: In the Linux kernel, the following vulnerability has been resolved: mm/khugepaged: write all dirty file folios when collapsing [There is no upstream commit, a

In the Linux kernel, the following vulnerability has been resolved: mm/khugepaged: write all dirty file folios when collapsing [There is no upstream commit, a

In the Linux kernel, the following vulnerability has been resolved: mm/khugepaged: write all dirty file folios when collapsing [There is no upstream commit, as this code was removed by upstream commit 044925f9b565 ("mm: fs: remove filemap_nr_thps*() functions and their users")] As-is, khugepaged and writable-file opening exclude each other. A file cannot be open writeable and have THPs (because the filesystem is not aware of them). khugepaged will never collapse file pages for files that are opened writeable. On an open(O_RDWR/O_WRONLY), the page cache for that particular file is dropped. This is fine because nothing could've been dirtied. However, there is an edge-case: collapse_file() might not be able to coexist with concurrent writers, but it can coexist with dirty folios (from previous writers). Therefore, the following can happen: open(file, O_RDWR) write(file) close(file) madvise(file_mapping, MADV_COLLAPSE, some non-dirty range) open(file, O_RDWR) nr_thps > 0 truncate_inode_pages() /* THPs are cleared out, but so are the dirty folios */ When this edge-case happens, there is data loss, as the dirty folios are fully discarded. Fix it by fully writing back the p

Description from the National Vulnerability Database, published by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

What it means for a small business

Linux is on the computers, phones or browsers your team uses every day. Turn on automatic updates and restart: most of these fixes only take effect after a restart.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.15%, higher than 4% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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