CVE-2019-12798
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 · uneditedAn issue was discovered in Artifex MuJS 1.0.5. regcompx in regexp.c does not restrict regular expression program size, leading to an overflow of the parsed syntax list size.
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 · high confidenceA buffer overflow vulnerability exists in Artifex MuJS 1.0.5 where the regcompx function in regexp.c fails to restrict regular expression program size, allowing specially crafted regex patterns to overflow the parsed syntax list buffer.
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= 1.0.5CVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/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 checksWork through these to decide whether this CVE applies to you.
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Identify MuJS installationLocate the MuJS library or binary in your environment. Check for files named 'mujs', 'libmujs', or 'mujs.dll' in common library directories, or look for it in project dependencies via package manager (npm, pip, etc.) or source code includes.Affected if MuJS library or executable is present in your environment
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Determine installed MuJS versionRun 'mujs --version' if the binary is accessible, or check the version string in the shared library file (e.g., 'strings libmujs.so | grep -i version' or similar). If using a package manager, check via 'npm list mujs', 'pip show mujs', or equivalent.Affected if The reported version is exactly 1.0.5
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Verify regex compilation is in useInspect application code for calls to MuJS regex functions, particularly js_newregexp() or equivalent regex compilation APIs. The vulnerable code path is triggered when compiling regex patterns via the regcompx function in regexp.c.Affected if Application code processes regex patterns through MuJS's regexp compilation functions
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Check for user-controlled regex inputReview code that passes regex patterns to MuJS. Determine if these patterns come from untrusted sources (user input, network input, file parsing of untrusted content).Affected if Untrusted or user-supplied regex patterns are passed to MuJS for compilation
You are affected if MuJS version 1.0.5 is installed AND your application compiles regex patterns, especially those derived from untrusted input.
Generated from the published advisory. Verify against your own configuration.
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.
dbcve · scopedUpgrade to MuJS version 1.0.6 or later which includes bounds checking in the regex compilation code.
MuJS 1.0.6 or later
- Identify the Mujs library version in your codebase by checking package.json, dependencies, or the compiled binary
- Locate the regexp.c file in the Mujs source code if compiling manually, or identify theMujs library file in your project dependencies
- Download Mujs version 1.0.6 or later from the official Ghostscript Git repository at git.ghostscript.com
- Replace the existing Mujs library files with the updated version
- Rebuild and recompile the application if compiling from source
- Re-run any automated tests to verify the fix does not break existing functionality
- Re-deploy the updated application
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,096.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-12798 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2019-12798 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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