# CVE-2026-25635: calibre: calibre is an e-book manager

CVE-2026-25635 is fixed in calibre on 1 platform, first by DEBIAN-CVE-2026-25635, released February 6, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-25635
- Priority: High
- CVSS: 8.6 (high)
- EPSS: 0.0050
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 6, 2026

## Description

calibre is an e-book manager. Prior to 9.2.0, Calibre's CHM reader contains a path traversal vulnerability that allows arbitrary file writes anywhere the user has write permissions. On Windows (haven't tested on other OS's), this can lead to Remote Code Execution by writing a payload to the Startup folder, which executes on next login. This vulnerability is fixed in 9.2.0.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | calibre Debian 12.15 (bookworm) | 6.13.0+repack-2+deb12u6 | [DEBIAN-CVE-2026-25635](https://patchblox.com/security/data/fix/linux/debian-cve-2026-25635.md) | Feb 6, 2026 |
| Linux | calibre Debian 13.5 (trixie) | 8.5.0+ds-1+deb13u2 | [DEBIAN-CVE-2026-25635](https://patchblox.com/security/data/fix/linux/debian-cve-2026-25635.md) | Feb 6, 2026 |
| Linux | calibre Debian 14 | 9.2.0+ds+~0.10.5-1 | [DEBIAN-CVE-2026-25635](https://patchblox.com/security/data/fix/linux/debian-cve-2026-25635.md) | Feb 6, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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