Is CVE-2026-30853 in the CISA KEV catalog?

No. CVE-2026-30853 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-30853?

CVE-2026-30853 has a CVSS v3 base score of 5.0 (MEDIUM).

What is the EPSS score for CVE-2026-30853?

CVE-2026-30853 has an EPSS score of 0.18% (8th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-30853?

Upgrade calibre on debian unstable to 9.5.0+ds+~0.10.5-1 or later. Fixes are available for 2 affected products.

CVE & CISA-KEV Catalog

CVE-2026-30853

MEDIUM

5.0

CVSS v3

NVD

Description

calibre is a cross-platform e-book manager for viewing, converting, editing, and cataloging e-books. Prior to 9.5.0, a path traversal vulnerability in the RocketBook (.rb) input plugin (src/calibre/ebooks/rb/reader.py) allows an attacker to write arbitrary files to any path writable by the calibre process when a user opens or converts a crafted .rb file. This is the same bug class fixed in CVE-2026-26065 for the PDB readers, but the fix was never applied to the RB reader. This vulnerability is fixed in 9.5.0.

CWE-22Path Traversal

How to fix

Remediation Available

calibreDebian

Fixed in:9.5.0+ds+~0.10.5-1CVE-2026-30853

calibreWindows application

Affected:9.5.0Fixed in:9.5.0Kovid Goyal

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal

Attack ComplexityLow

Privileges RequiredNone

User InteractionRequired

ScopeChanged

Impact

ConfidentialityNone

IntegrityLow

AvailabilityLow

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:L

Exploit Intelligence

0.18%probability of exploitation in 30 days

8thpercentile

Low risk: more likely to be exploited than 8% of all known CVEs.

References

Exploit1

github.com

Related Vulnerabilities

Other CWE-22 (Path Traversal) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2024-23897	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2023-32315	High	8.6	100%	KEV	Fix
CVE-2022-29464	Critical	9.8	100%	KEV + Ransom	-
CVE-2021-26086	Medium	5.3	100%	KEV	Fix
CVE-2021-22005	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2020-5902	Critical	9.8	100%	KEV + Ransom	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-03-18.