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Fencer Intel
medium 6.5

CVE-2018-19839 json

In LibSass prior to 3.5.5, the function handle_error in sass_context.cpp allows attackers to cause a denial-of-service resulting from a hea…

published 7y ago modified 4mo ago also EUVD-2018-11514

cvss
6.5
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.2%
EPSS 2.2% chance of exploitation in 30 days, percentile 82%
public exploits
0
none known

Summary

In LibSass prior to 3.5.5, the function handle_error in sass_context.cpp allows attackers to cause a denial-of-service resulting from a heap-based buffer over-read via a crafted sass file.

Patch / fix

  • sass-lang libsass 3.5.5
  • libsass Debian 14, Debian 13, Debian 12 3.5.5-4

debian advisories DEBIAN-CVE-2018-19839

  • libsass Ubuntu Pro 18.04 LTS 3.4.8-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2018-19839

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • libsass Package Hub 15 SP1 3.6.1-bp151.4.3.1
  • libsass Package Hub 15 3.6.1-bp150.3.3.1
  • libsass openSUSE Leap 15.1, openSUSE Leap 15.0 3.6.1-lp151.3.3.1

opensuse advisories openSUSE-SU-2019:1883-1openSUSE-SU-2019:1800-1openSUSE-SU-2019:1791-1

Is CVE-2018-19839 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2018-19839 updated cvss 3.3

libsass: Heap-based buffer over-read in the handle_error function resulting in a denial of service

  • Red Hat Enterprise Linux 8 libsass
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.16% chance of exploitation in the next 30 days, higher than 82% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/sass/libsass/issues/2657 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 6.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.