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CVE-2026-25636

Calibre-ebook Calibre code injection

8.2 HIGHPublic exploitEPSS 0.18%
  1. Published6 Feb 2026

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 breakdown

Attack vectorLocal
Attack complexityLow
Privileges requiredNone
User interactionRequired
ScopeChanged
ConfidentialityNone
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:H

Affected products

Calibre-ebook Calibre< 9.2.0

Remediation

Fixed in
Calibre-ebook Calibre≥ 9.2.0

References

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Frequently asked

Is CVE-2026-25636 being actively exploited?

CVE-2026-25636 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.18%.

How severe is CVE-2026-25636?

CVE-2026-25636 has a CVSS 3.1 base score of 8.2, rated high. EPSS estimates a 0.18% probability of exploitation.

Which products are affected by CVE-2026-25636?

Affected products include Calibre-ebook Calibre.

How do I fix CVE-2026-25636?

Upgrade affected software to a fixed version, for example Calibre-ebook Calibre 9.2.0 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-25636 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.