SZB-ab1ec73152
libass memory flaw in event pruning affects 0.17.4 to 0.17.5 (EUVD-2026-114006)
- Status
- Unverified: only social posts report this so far
- Kind
- Vulnerability
- Vendor
- libass
- Product
- libass
- First seen
Summary
The EUVD record, updated October 30, 2026, rates this flaw 7.3/10 (CVSS v3.1). It says negative Matroska ReadOrder values are not guarded during event pruning in libass versions 0.17.4 through 0.17.5.
If you use libass
Update libass to version 0.17.5 or later
Update applications that bundle libass, such as media players
Avoid opening untrusted subtitle files until patched
Avoid rendering untrusted ASS subtitle files until patched
What the sources say 2
· Mastodon: “Prior to 0.17.5, libass can overread and overwrite the glyph array in `wrap_lines_measure` while rendering malicious `ASS` content.” Source
· Mastodon: “From 0.17.4 until 0.17.5, libass event pruning does not guard negative Matroska `ReadOrder` values, allowing an attacker to clear arbitrarily...” Source