CVE-2026-25636

Name: CVE-2026-25636
Creator: NVD / NIST
Published: 2026-02-06T21:16:18.833+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 0.21%

Last modified Jun 17, 2026

CVE-2026-25636 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. calibre is an e-book manager. In 9.1.0 and earlier, a path traversal vulnerability in Calibre's EPUB conversion allows a malicious EPUB file to corrupt arbitrary existing files writable by the Calibre process. EPSS estimates a 0.21% chance of exploitation in the next 30 days.

Description

calibre is an e-book manager. In 9.1.0 and earlier, a path traversal vulnerability in Calibre's EPUB conversion allows a malicious EPUB file to corrupt arbitrary existing files writable by the Calibre process. During conversion, Calibre resolves CipherReference URI from META-INF/encryption.xml to an absolute filesystem path and opens it in read-write mode, even when it points outside the conversion extraction directory. This vulnerability is fixed in 9.2.0.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

0.21%

11.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Calibre-Ebook	Calibre	< 9.2.0

References

https://github.com/kovidgoyal/calibre/commit/9484ea82c6ab226c18e6ca5aa000fa16de598726Patch
https://github.com/kovidgoyal/calibre/security/advisories/GHSA-8r26-m7j5-hm29Exploit, Third Party Advisory
https://0x5t.raptx.org/posts/calibre-epub-rceExploit, Third Party Advisory

Timeline

Published: Feb 6, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-25636?

How severe is CVE-2026-25636?

CVE-2026-25636 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.

How do I fix CVE-2026-25636?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-25636?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST