Aegisub executes arbitrary code through automatically loaded Automation scripts
Published Oct 9, 2026 · Updated Oct 24, 2026
Original summary
Normalized public record · Updated Oct 24, 2026
Aegisub executes arbitrary code through automatically loaded Automation scripts
Publisher and source text is retained separately from QFinch interpretation.
QFinch assessment
Aegisub is a cross-platform advanced subtitle editor. From 3.2.0 to 3.4.2, Aegisub automatically loads Automation scripts referenced by `Automation Scripts` metadata in `ASS` subtitle projects without asking whether the user trusts the scripts or their authors. An attacker can distribute a crafted `ASS` file together with a referenced malicious Automation script, and opening the `AS` file executes arbitrary code with the privileges of the Aegisub process. From 3.4.0 to 3.4.2, inconsistent handling of embedded `NUL` characters between extension validation and filesystem operations additionally allows a crafted `ASS/Lua` polyglot to reference and execute itself as a single-file variant. The vulnerability is fixed in Aegisub 3.5.0.
Evidence: public source recordsAffected products
| Affected package, product or range | Fix status |
|---|---|
| Consult the referenced vendor advisory for affected versions. | Consult source advisory |
Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.
Remediation
Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.
- Confirm the affected product and reachable code path exist in your environment.
- Apply the vendor-supported patch or mitigation from the primary advisory.
- Rescan the exact deployed revision and retain verification evidence.
Evidence coverage
- SSVC priority
- MEDIUM
- Confidence
- 10%
- Aliases
- None reported
Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.
Sources and record history
Record history
Published Oct 9, 2026 · Last refreshed Oct 24, 2026