How severe is CVE-2019-18799?

CVE-2019-18799 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-2019-18799 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-18799?

CVE-2019-18799 affects Sass-lang Libsass. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2019-18799?

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

When was CVE-2019-18799 published?

CVE-2019-18799 was published on 2019-11-06 and last updated on 2026-06-17.

CVE-2019-18799

CVE-2019-18799 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-476.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.3
EPSS exploit prediction: 1% (66th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-476
Affected product: Sass-lang Libsass
Published: 2019-11-06
Last modified: 2026-06-17

Description

LibSass before 3.6.3 allows a NULL pointer dereference in Sass::Parser::parseCompoundSelector in parser_selectors.cpp.

Frequently asked questions

What is CVE-2019-18799?: LibSass before 3.6.3 allows a NULL pointer dereference in Sass::Parser::parseCompoundSelector in parser_selectors.cpp.
How severe is CVE-2019-18799?: CVE-2019-18799 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-2019-18799 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-18799?: CVE-2019-18799 affects Sass-lang Libsass. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-18799?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2019-18799 published?: CVE-2019-18799 was published on 2019-11-06 and last updated on 2026-06-17.

References

https://github.com/sass/libsass/issues/3001

Affected products (1)

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

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