dm array: validate array block headers on read
CVE-2026-89574 · published 11 Sept 2026
How serious is it
- Severity: high, CVSS score 7.8 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-89574?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- Linux Linux: 6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to < 0e3b8f371c385c212b6e6f76c66f5b3f5bcfea62, 6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to < 67adda7ed5da3e3b64f5b9021a02c21fb374fd9c, 6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to < b33f76d33aaeacf3baf3370d8d64985169b36600, 6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to < 9808ddffb4bc659352df3020cd84d9d864820ee5
- Linux Linux: 3.9
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
In the Linux kernel, the following vulnerability has been resolved:
dm array: validate array block headers on read
array_block_check() validates blocknr and csum and nothing else, while
node_check(), next to it, has bounded the structural fields since both
were written. dm_array_cursor_next() takes its loop bound from the
on-disk nr_entries and element_at() is unguarded pointer arithmetic, so
a count larger than the block holds keeps the cursor in one block while
the index grows past it and the read walks off the dm-bufio buffer --
dm_cache_load_mappings() drives it once per cache block at activation.
Check the header against itself: reject a zero value_size, require
max_entries to equal calc_max_entries() for that value_size and block
size, and require nr_entries to fit. Equality rather than an upper bound,
since a count below the real capacity trips BUG_ON() in fill_ablock() and
trim_ablock(). Metadata dm-array writes satisfies all three.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- git.kernel.org/stable/c/0e3b8f371c385c212b6e6f76c66f5b3f5bcfea62
- git.kernel.org/stable/c/67adda7ed5da3e3b64f5b9021a02c21fb374fd9c
- git.kernel.org/stable/c/b33f76d33aaeacf3baf3370d8d64985169b36600
- git.kernel.org/stable/c/9808ddffb4bc659352df3020cd84d9d864820ee5
- git.kernel.org/stable/c/2965787723084835b18dfe993cd450ebf5bd4540
Merged from CVE List. Last updated 26 Oct 2026. All vulnerabilities · RSS · JSON