CVE-2026-27810: calibre Vulnerable to HTTP Response Header Injection
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 contentdisposition 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 Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-27810?
CVE-2026-27810 is categorized as a medium severity vulnerability due to its potential exploitation by authenticated users.
How do I fix CVE-2026-27810?
To fix CVE-2026-27810, upgrade calibre to version 9.4.0 or later.
Who is affected by CVE-2026-27810?
Any user running calibre versions prior to 9.4.0 is affected by CVE-2026-27810.
What type of vulnerability is CVE-2026-27810?
CVE-2026-27810 is an HTTP Response Header Injection vulnerability.
Can CVE-2026-27810 be exploited remotely?
CVE-2026-27810 requires an authenticated user to exploit the vulnerability.