Description
In LibSass 3.5.5, a NULL Pointer Dereference in the function Sass::Selector_List::populate_extends in SharedPtr.hpp (used by ast.cpp and ast_selectors.cpp) may cause a Denial of Service (application crash) via a crafted sass input file.
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 16.04 LTS | libsass | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | libsass | 3.4.8-1ubuntu0.1~esm1 | USN-4837-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 15 SP1 | libsass | 3.6.1-bp151.4.3.1 | openSUSE-SU-2019:1883-1 |
| SUSE Package Hub 15 | libsass | 3.6.1-bp150.3.3.1 | openSUSE-SU-2019:1800-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.1 | libsass | 3.6.1-lp151.3.3.1 | openSUSE-SU-2019:1791-1 |
| openSUSE Leap 15.0 | libsass | 3.6.1-lp151.3.3.1 | openSUSE-SU-2019:1791-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 2 (CBL-Mariner) | reaper | 3.1.1-21 | — |
Advisories 5
- USN-4837-1 libsass vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- openSUSE-SU-2019:1800-1 Security update for libsass SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2019:1883-1 Security update for libsass SUSE / openSUSE Security Updates · May 7, 2025
- openSUSE-SU-2019:1791-1 Security update for libsass SUSE / openSUSE Security Updates · May 7, 2025
- WID-SEC-2023-0809 IBM QRadar SIEM: Mehrere Schwachstellen BSI CERT-Bund (WID) · Feb 19, 2024
References
- https://github.com/sass/libsass/issues/2779
- openSUSE-SU-2019:1791 vendor-advisory
- openSUSE-SU-2019:1800 vendor-advisory
- openSUSE-SU-2019:1883 vendor-advisory