High severity · published Feb 6, 2026
CVE-2026-25731
Calibre Affected by Arbitrary Code Execution via Server-Side Template Injection in Calibre HTML Export
7.8
CVSS
0.3%
EPSS
No
On KEV
Description
calibre is an e-book manager. Prior to 9.2.0, a Server-Side Template Injection (SSTI) vulnerability in Calibre's Templite templating engine allows arbitrary code execution when a user converts an ebook using a malicious custom template file via the --template-html or --template-html-index command-line options. This vulnerability is fixed in 9.2.0.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 20% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CA
calibre · kovidgoyal
< 9.2.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-25731
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-25731
Patch
https://github.com/kovidgoyal/calibre/commit/f0649b27512e987b95fcab2e1e0a3bcdafc23379
Exploit
https://github.com/kovidgoyal/calibre/security/advisories/GHSA-xrh9-w7qx-3gcc
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