CVE-2026-25636
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.22%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- EPSS
- 0.22% probability · 12th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-22, CWE-73, CWE-94
- Affected
- calibre-ebook/calibre
- Source
- security-advisories@github.com
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.