How severe is CVE-2018-19838?

CVE-2018-19838 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2018-19838 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-19838?

CVE-2018-19838 affects Sass-lang Libsass. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-19838?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-19838 published?

CVE-2018-19838 was published on 2018-12-04 and last updated on 2026-06-17.

CVE-2018-19838

CVE-2018-19838 is a medium-severity vulnerability in Sass-lang Libsass with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-400.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.3
EPSS exploit prediction: 2% (78th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-400
Affected product: Sass-lang Libsass
Published: 2018-12-04
Last modified: 2026-06-17

Description

In LibSass prior to 3.5.5, functions inside ast.cpp for IMPLEMENT_AST_OPERATORS expansion allow attackers to cause a denial-of-service resulting from stack consumption via a crafted sass file, as demonstrated by recursive calls involving clone(), cloneChildren(), and copy().

Frequently asked questions

What is CVE-2018-19838?: In LibSass prior to 3.5.5, functions inside ast.cpp for IMPLEMENT_AST_OPERATORS expansion allow attackers to cause a denial-of-service resulting from stack consumption via a crafted sass file, as demonstrated by recursive calls involving clone(), cloneChildren(), and copy().
How severe is CVE-2018-19838?: CVE-2018-19838 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2018-19838 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-19838?: CVE-2018-19838 affects Sass-lang Libsass. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-19838?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-19838 published?: CVE-2018-19838 was published on 2018-12-04 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:sass-lang:libsass:*:*:*:*:*:*:*:*

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