Vulnerability · Published Mar 27, 2026 · Assigned by GitHub_M

CVE-2026-33205calibre has Server-Side Request Forgery in ebook viewer backend

Medium 4.8

In plain English

A medium-severity server-side request forgery in calibre from kovidgoyal. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)4.8Medium

Exploit odds (30 days)0.2%top 92.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

calibre is a cross-platform e-book manager for viewing, converting, editing, and cataloging e-books. Prior to version 9.6.0, a Server-Side Request Forgery vulnerability in the background-image endpoint of calibre e-book reader's web view allows an attacker to perform blind GET requests to arbitrary URLs and exfiltrate information out from the ebook sandbox. Version 9.6.0 patches the issue.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	calibre	6.13.0+repack-2+deb12u9	DEBIAN-CVE-2026-33205
Debian:13	calibre	8.5.0+ds-1+deb13u3	DEBIAN-CVE-2026-33205
Debian:14	calibre	9.6.0+ds+~0.10.5-1	DEBIAN-CVE-2026-33205
Ubuntu:22.04:LTS	calibre	no fix listed	UBUNTU-CVE-2026-33205
Ubuntu:24.04:LTS	calibre	no fix listed	UBUNTU-CVE-2026-33205
Ubuntu:25.10	calibre	no fix listed	UBUNTU-CVE-2026-33205
Ubuntu:26.04:LTS	calibre	no fix listed	UBUNTU-CVE-2026-33205
Ubuntu:26.10	calibre	no fix listed	UBUNTU-CVE-2026-33205

Affected products (as reported)

Vendor	Product	Versions
kovidgoyal	calibre	< 9.6.0

Weakness: CWE-918 · Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

References

https://github.com/kovidgoyal/calibre/security/advisories/GHSA-4926-v9px-wv7v x_refsource_CONFIRM