CVE-2026-30853

low-risk
Published 2026-03-13

calibre is a cross-platform e-book manager for viewing, converting, editing, and cataloging e-books. Prior to 9.5.0, a path traversal vulnerability in the RocketBook (.rb) input plugin (src/calibre/ebooks/rb/reader.py) allows an attacker to write arbitrary files to any path writable by the calibre process when a user opens or converts a crafted .rb file. This is the same bug class fixed in CVE-2026-26065 for the PDB readers, but the fix was never applied to the RB reader. This vulnerability is fixed in 9.5.0.

Do I need to act?

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0.01% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
5
CVSS 5.0/10 Medium
LOCAL / LOW complexity

Affected Products (1)

Affected Vendors

22
/ 100
low-risk
Severity 17/34 · Moderate
Exploitability 0/34 · Minimal
Exposure 5/34 · Minimal