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OpenAdvisories
Medium · 6.4 CVE-2026-27810 EUVD-2026-9056

calibre Vulnerable to HTTP Response Header Injection

Published Feb 27, 2026 · Updated Mar 2, 2026 · Assigned by GitHub_M

Description

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.

Affected products

VendorProductAffectedFixed
kovidgoyal calibre < 9.4.0 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 calibre 9.4.0+ds+~0.10.5-1 —
Debian 13 calibre 8.5.0+ds-1+deb13u2 —
Debian 12 calibre 6.13.0+repack-2+deb12u6 —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 calibre No fix yet —
Ubuntu 26.04 LTS calibre No fix yet —
Ubuntu 25.10 calibre No fix yet —
Ubuntu 24.04 LTS calibre No fix yet —
Ubuntu 22.04 LTS calibre No fix yet —
Show 3 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 20.04 LTS calibre No fix yet —
Ubuntu 18.04 LTS calibre No fix yet —
Ubuntu 16.04 LTS calibre No fix yet —
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed calibre 9.7.0-1.1 openSUSE-SU-2026:10587-1

Advisories 1

References