CVE-2026-26064

Severity CVSS v4.0:

CRITICAL

Type:

CWE-22 Path Traversal

Publication date:

20/02/2026

Last modified:

20/02/2026

Description

calibre is a cross-platform e-book manager for viewing, converting, editing, and cataloging e-books. Versions 9.2.1 and below contain a Path Traversal vulnerability that allows arbitrary file writes anywhere the user has write permissions. On Windows, this leads to Remote Code Execution by writing a payload to the Startup folder, which executes on next login. Function extract_pictures only checks startswith(&#39;Pictures&#39;), and does not sanitize &#39;..&#39; sequences. calibre&#39;s own ZipFile.extractall() in utils/zipfile.py does sanitize &#39;..&#39; via _get_targetpath(), but extract_pictures() bypasses this by using manual zf.read() + open(). This issue has been fixed in version 9.3.0.

Impact

Vector 4.0

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H CVSS v4.0 Severity and Metrics:

Base Score: 9.30 CRITICAL
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Attack Vector (AV): Local
Attack Complexity (AC): Low
Attack Requirements (AT): None
Privileges Required (PR): None
User Interaction (UI): Active
Confidentiality (VC): High
Integrity (VI): High
Availability (VA): High
Confidentiality (SC): High
Integrity (SI): High
Availability (SA): High

Base Score 4.0

9.30

Severity 4.0

CRITICAL

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 8.80 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High