RCE in Calibre-Ebook Calibre
CVE-2026-25636
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.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:H.
EPSS exploit prediction
EPSS: 0.002 (4.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 4.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: -0.000
Affected products
- Calibre-Ebook Calibre
- Kovidgoyal Calibre — versions < 9.2.0
Weakness classification (CWE)
References
- github.com/kovidgoyal/calibre/security/advisories/GHSA-8r26-m7j5-hm29 (Exploit, Third Party Advisory)
- github.com/kovidgoyal/calibre/commit/9484ea82c6ab226c18e6ca5aa000fa16de598726 (Patch)
- af854a3a-2127-422b-91ae-364da2661108 (Exploit, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-25636?
- CVE-2026-25636 is a high-severity vulnerability in Calibre-Ebook Calibre, classified under Path Traversal. CVSS score: 8.2/10. Published 2026-02-06.
- How severe is CVE-2026-25636?
- High severity. CVSS v3 base score is 8.2 out of 10.