CVE-2026-27810
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.
How to fix CVE-2026-27810
No fixed version has been published yet. Mitigate by removing the affected package or applying upstream guidance from the references below.
- —no fix listed
Is CVE-2026-27810 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N |