CVE-2026-8398: Daemon Tools Lite Embedded Malicious Code Vulnerability

In short

Daemon Daemon Tools Lite has a weakness classified as embedded malicious code (CWE-506). CISA added it to its Known Exploited Vulnerabilities catalog on 2026-05-27. NVD lists CVSS 4.0 at 9.3 CRITICAL.

What it is

“Daemon Tools contains an unspecified vulnerability that has a high impact on confidentiality, integrity, and availability.” — CISA KEV, retrieved 2026-11-01

“A supply chain attack compromised the official installation packages of DAEMON Tools Lite (Windows versions 12.5.0.2421 through 12.5.0.2434), distributed from the legitimate website daemon-tools.cc between approximately April 8, 2026, and May 5, 2026. Attackers gained unauthorized access to the vendor's (AVB Disc Soft) build or distribution infrastructure and trojanized three binaries: DTHelper.exe, DiscSoftBusServiceLite.exe, and DTShellHlp.exe. These files were digitally signed with the legitimate AVB Disc Soft code-signing certificate, allowing the malicious installers to appear trustworthy and bypass signature-based detection.” — NVD, retrieved 2026-11-01

Who is affected

Daemon Daemon Tools Lite. NVD lists the following versions as affected:

• Versions version 12.5.1

Exploitation status

CISA KEV added: 2026-05-27. Known ransomware campaign use: Not reported by CISA. Due date CISA set for US federal civilian agencies: 2026-05-30.

Scores

NVD CVSS 4.0: 9.3 CRITICAL; vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/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; source [email protected].

EPSS by FIRST: 1.46%; percentile 73.50; score date 2026-10-31. EPSS estimates the probability of exploitation in the next 30 days.

CWE: CWE-506.

Timeline

CISA required action

“Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.” — CISA KEV

What to do

• Confirm whether you run Daemon Daemon Tools Lite and which version.
• Apply the vendor update or mitigation in the advisory.
• Follow CISA’s required action.
• Review the vendor guidance on signs of compromise.
• Track the fix through completion.

References

• Vendor Advisory: https://blog.daemon-tools.cc/post/security-incident
• NVD detail
• CVE.org record
• CISA KEV catalog

Sources and dates

CISA Known Exploited Vulnerabilities Catalog, version 2026.10.30; retrieved 2026-11-01. CISA KEV data: CC0 1.0. No endorsement by CISA.

NVD retrieved: 2026-11-01. This product uses the NVD API but is not endorsed or certified by the NVD.

EPSS scores by FIRST; score date 2026-10-31.