CVE-2026-8398
Daemon Tools Lite Embedded Malicious Code Vulnerability
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.
Published Updated Sources: NVD, AVB Disc Soft (CNA), CISA, FIRST EPSS, GitHub, GitHub Security Advisory
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Confirmed
CISA KEV, listed May 27, 2026
EPSS
1%
ahead of 71% of scored CVEs
CVSS base
9.8
critical · 2 sources
CISA SSVC assessment
Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.
Exploitation
Active
none · proof-of-concept · active
Automatable
Yes
can an attacker script all four kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component
Remediation
The vendor's own words where we have them.
Users of potentially infected application are recommended to uninstall the application, run a full system scan using antivirus software with the latest version of the anti-virus databases, and install the latest version of DAEMON Tools Lite (12.6 or newer) from the official website.
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.
Federal deadline May 30, 2026 — passed 87 days ago
First 24 hours
Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.
- Identify exposed assets running affected vendor/product/version combinations.
- Treat as emergency remediation because CISA KEV status is present.
- Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.
Affected scope
Vendor, product and version as the advisories word them.
| Vendor | Product | Versions | Status |
|---|---|---|---|
| AVB Disc Soft | DAEMON Tools Lite | 12.5.0.2421 to < 2.6.0.* | Vulnerable |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Availability
High
Confidentiality
High
Integrity
High
Scope
Unchanged
Attack Complexity
Low
Attack Vector
Network
Privileges Req
None
User Interaction
None
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 9.8 | CVSS 3.1 | critical | 3.9 | 5.9 | kaspersky.com (CNA), AVB Disc Soft (CNA), GHSA |
| 9.3 | CVSS 4.0 | critical | — | — | AVB Disc Soft (CNA) |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness & attack patterns
- CWE-506
Inferred from the weakness class — not observed against this CVE.
- T1195.001Supply Chain Compromise: Compromise Software Dependencies and Development Tools
- T1195.002Supply Chain Compromise: Compromise Software Supply Chain
- T1027.009Obfuscated Files or Information: Embedded Payloads
CISA KEV details
CISA lists a CVE here once it has evidence of exploitation against real targets.
Listed
May 27, 2026
Federal deadline
May 30, 2026
passed 87 days ago
Ransomware use
Unknown
CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a date to argue against.
Public exploit
Capability, not use: code existing is a different claim from anyone running it.
Repositories
5
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Prioritize edge telemetry for network-reachable DAEMON Tools Lite.
- Monitor for scanner or exploit-pattern traffic after 5 public PoC repositories were reported.
Timeline
What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.
- 2026
Added · CVSS 3.1 9.8 (AV:N)
Jun 17, 2026 · NVD
Added to CISA KEV catalog
May 27, 2026 · CISA
Initial · CVE published
May 15, 2026 · NVD
Added · GHSA-rm3r-35x9-jv93 published (critical)
May 15, 2026 · GitHub Security Advisory
Reported · Advisory published by vendor
May 6, 2026 · AVB Disc Soft
References
5 on the record
- blog.daemon-tools.cc/post/security-incident
Vendor Advisory
- securelist.com/tr/daemon-tools-backdoor/119654/
Exploit, Third Party Advisory, Vendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-8398
US Government Resource
- nvd.nist.gov/vuln/detail/CVE-2026-8398
NVD, Vendor Advisory
- github.com/advisories/GHSA-rm3r-35x9-jv93
Exploit, Third Party Advisory
Elsewhere on this site
- AVB Disc Softevery CVE for this vendor
- May 2026what else CISA listed
- Remote Code Execsame class
- CWE-506other pages naming this weakness
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record1
What should defenders know first?
CVE-2026-8398 is Daemon Tools Lite Embedded Malicious Code Vulnerability, a critical vulnerability affecting DAEMON Tools Lite from AVB Disc Soft. The current evidence lists it in CISA KEV, and the exploit status is: Yes: CISA KEV signal present. Public exploit evidence is: 5 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 9.8 describes technical severity, while EPSS 1% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.