How severe is CVE-2026-33206?

CVE-2026-33206 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-33206 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33206?

CVE-2026-33206 affects Calibre-ebook Calibre. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-33206?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-33206 have an EU (EUVD) identifier?

Yes. CVE-2026-33206 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16612.

When was CVE-2026-33206 published?

CVE-2026-33206 was published on 2026-03-27 and last updated on 2026-06-17.

CVE-2026-33206

CVE-2026-33206 is a medium-severity vulnerability in Calibre-ebook Calibre with a CVSS 3.x base score of 6.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-23.

Key facts

Severity: Medium (CVSS 3.x base score 6.3)
CVSS v4: 8.2
EPSS exploit prediction: 0% (11th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-16612
Weakness: CWE-23
Affected product: Calibre-ebook Calibre
Published: 2026-03-27
Last modified: 2026-06-17

Description

calibre is a cross-platform e-book manager for viewing, converting, editing, and cataloging e-books. Prior to version 9.6.0, a path traversal vulnerability exists in Calibre' handling of images in Markdown and other similar text-based files allowing an attacker to include arbitrary files from the file system into the converted book. Additionally, missing authentication and server-side request forgery in the background-image endpoint in the ebook reader web view allow the files to be exfiltrated without additional interaction. Version 9.6.0 contains a fix.

Frequently asked questions

What is CVE-2026-33206?: calibre is a cross-platform e-book manager for viewing, converting, editing, and cataloging e-books. Prior to version 9.6.0, a path traversal vulnerability exists in Calibre' handling of images in Markdown and other similar text-based files allowing an attacker to include arbitrary files from the file system into the converted book. Additionally, missing authentication and server-side request forgery in the background-image endpoint in the ebook reader web view allow the files to be exfiltrated without additional interaction. Version 9.6.0 contains a fix.
How severe is CVE-2026-33206?: CVE-2026-33206 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-33206 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33206?: CVE-2026-33206 affects Calibre-ebook Calibre. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-33206?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-33206 have an EU (EUVD) identifier?: Yes. CVE-2026-33206 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16612.
When was CVE-2026-33206 published?: CVE-2026-33206 was published on 2026-03-27 and last updated on 2026-06-17.

References

https://github.com/kovidgoyal/calibre/security/advisories/GHSA-h3p4-m74f-43g6

Affected products (1)

cpe:2.3:a:calibre-ebook:calibre:*:*:*:*:*:*:*:*

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