What is CVE-2026-25731?

CVE-2026-25731 is a high-severity vulnerability in Kovidgoyal Calibre, classified under Improper Neutralization of Special Elements Used in a Template Engine. CVSS score: 7.8/10. Published 2026-02-06.

How severe is CVE-2026-25731?

High severity. CVSS v3 base score is 7.8 out of 10.

Vulnerability in Kovidgoyal Calibre

CVE-2026-25731

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 fil…

EPSS: 0.000 (3.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Kovidgoyal Calibre — versions < 9.2.0

Weakness classification (CWE)

CWE-1336 — Improper Neutralization of Special Elements Used in a Template Engine

References

https://github.com/kovidgoyal/calibre/security/advisories/GHSA-xrh9-w7qx-3gcc (x_refsource_CONFIRM)
https://github.com/kovidgoyal/calibre/commit/f0649b27512e987b95fcab2e1e0a3bcdafc23379 (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-25731?: CVE-2026-25731 is a high-severity vulnerability in Kovidgoyal Calibre, classified under Improper Neutralization of Special Elements Used in a Template Engine. CVSS score: 7.8/10. Published 2026-02-06.
How severe is CVE-2026-25731?: High severity. CVSS v3 base score is 7.8 out of 10.