Description
An issue was discovered in LibSass through 3.5.4. An out-of-bounds read of a memory region was found in the function Sass::Prelexer::exactly() which could be leveraged by an attacker to disclose information or manipulated to read from unmapped memory causing a denial of service.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libsass | 3.6.3-1 | — |
| Debian 13 | libsass | 3.6.3-1 | — |
| Debian 12 | libsass | 3.6.3-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | libsass | 3.4.8-1ubuntu0.1~esm1 | USN-4837-1 |
Advisories 1
- USN-4837-1 libsass vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026