LibsassApplication · Sass Lang

CVE-2018-19827

HIGH · 8.8 CVSS v3.0 Published 2018-12-03
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In LibSass 3.5.5, a use-after-free vulnerability exists in the SharedPtr class in SharedPtr.cpp (or SharedPtr.hpp) that may cause a denial of service (application crash) or possibly have unspecified other impact.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

LibSass 3.5.5 contains a use-after-free vulnerability in the SharedPtr class (SharedPtr.cpp or SharedPtr.hpp). The issue allows an attacker to potentially trigger memory corruption by accessing memory after it has been freed, leading to denial of service through application crashes or possibly other unspecified impact.

MitigationUpgrade LibSass to a patched version that addresses the use-after-free in SharedPtr. If immediate upgrade is not feasible, audit any applications or systems using LibSass 3.5.5 for potential exploitation vectors.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
LibsassApplication
Affected:= 3.5.5

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed LibSass version
    Run 'libsass --version' or check the library binary metadata. If using a package manager (npm, gem, etc.), run 'npm list libsass' or equivalent to query the installed version.
    Affected if The installed version is exactly 3.5.5 (note: other versions may also be vulnerable but only 3.5.5 is confirmed affected in this CVE)
  2. Locate SharedPtr source files
    Search for SharedPtr.cpp or SharedPtr.hpp in the LibSass installation directory or source tree: 'find /path/to/libsass -name "SharedPtr.cpp" -o -name "SharedPtr.hpp"'
    Affected if These files exist in the LibSass version being used, indicating the vulnerable code is present
  3. Inspect SharedPtr.cpp or SharedPtr.hpp for use-after-free patterns
    Examine the SharedPtr.cpp or SharedPtr.hpp source file for the vulnerable code path that allows accessing freed memory. Look for any code that dereferences a shared pointer after it has been released or reset.
    Affected if The vulnerable code pattern exists in the SharedPtr implementation and the application exercises that code path

A user is affected if LibSass version 3.5.5 is installed and any application or process actively uses LibSass to compile Sass stylesheets, as this triggers the vulnerable SharedPtr code path.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade LibSass to a patched version that addresses the use-after-free in SharedPtr. If immediate upgrade is not feasible, audit any applications or systems using LibSass 3.5.5 for potential exploitation vectors.

Fix this in Libsass Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing6.0 h
  • Review / QA3.0 h
14.0 hours of engineering $2,400
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-19827 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data