SSRF in Calibre-Ebook Calibre

CVE-2026-33205

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.

Vulnerability class: SSRF (Server-Side Request Forgery)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.002 (5.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 6th percentile — 5.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-33205: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: -0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-33205?
CVE-2026-33205 is a medium-severity vulnerability in Calibre-Ebook Calibre, classified under Server-Side Request Forgery (SSRF). CVSS score: 5.5/10. Published 2026-03-27.
How severe is CVE-2026-33205?
Medium severity. CVSS v3 base score is 5.5 out of 10.