CVE-2026-27810

calibre: calibre is a cross-platform e-book manager for viewing, converting, editing, and cataloging e-books

CVE-2026-27810 is fixed in calibre on 1 platform, first by DEBIAN-CVE-2026-27810, released February 27, 2026. It is not reported as exploited. Patch Radar priority: Routine.

Routine
CVSS
6.4
medium
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0024
15th percentile

calibre is a cross-platform e-book manager for viewing, converting, editing, and cataloging e-books. Prior to version 9.4.0, an HTTP Response Header Injection vulnerability in the calibre Content Server allows any authenticated user to inject arbitrary HTTP headers into server responses via an unsanitized `content_disposition` query parameter in the `/get/` and `/data-files/get/` endpoints. All users running the calibre Content Server with authentication enabled are affected. The vulnerability is exploitable by any authenticated user and can also be triggered by tricking an authenticated victim into clicking a crafted link. Version 9.4.0 contains a fix for the issue.

Where it's fixed

ProductFixed inFixReleased
Linux
calibre · Debian 12.15 (bookworm) 6.13.0+repack-2+deb12u6 DEBIAN-CVE-2026-27810 Feb 27, 2026
calibre · Debian 13.5 (trixie) 8.5.0+ds-1+deb13u2 DEBIAN-CVE-2026-27810 Feb 27, 2026
calibre · Debian 14 9.4.0+ds+~0.10.5-1 DEBIAN-CVE-2026-27810 Feb 27, 2026

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