Review reviewHigh

CVE-2026-55408

koodo-reader

Koodo Reader is an ebook reader. In version 2.3.0 and earlier, Koodo Reader is vulnerable to remote code execution through malicious EPUB files because the open-book IPC handler enables nodeIntegrationInSubFrames and EPUB chapter content is rendered with unsanitized innerHTML. An attacker can craft an EPUB book that, when imported and opened by the victim, instantiates a hidden iframe with Node.js API access and executes arbitrary operating system commands with the victim user's privileges. This issue is fixed in version 2.3.1.

CVSS: 8.4
EPSS: 0.19%
CISA KEV: Not listed
Published: 2026.07.08

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.19%

Technical severityCVSS 8.4

Vulnerability overview

Affected product and versions

Product: koodo-reader
Affected versions: < 2.3.1
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that koodo-reader and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CWE: CWE-94