CVE-2026-92705: Aegisub executes arbitrary code through automatically loaded Automation scripts
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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Aegisubto a version that resolves this vulnerability.Fixed in 3.5.0
Event History
Frequently Asked Questions
Which users are exposed to the single-file attack variant?
The single-file ASS/Lua polyglot variant affects Aegisub versions 3.4.0 through 3.4.2. It relies on inconsistent embedded-NUL handling between extension validation and filesystem operations.
What must an attacker provide for exploitation?
For the standard variant, an attacker must distribute a crafted ASS subtitle project together with a malicious Automation script referenced in its Automation Scripts metadata. Opening the ASS file causes Aegisub to load the referenced script automatically.
Does exploitation require elevated privileges or additional user actions after opening the file?
No privileges are required from the attacker, but the victim must open the crafted file. Code executes with the privileges of the Aegisub process.
What version remediates this issue?
Aegisub 3.5.0 fixes the vulnerability. Versions 3.2.0 through 3.4.2 are affected by automatic loading of referenced Automation scripts.