Debian LinuxOperating system · Debian
CVE-2020-26519
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 · uneditedArtifex MuPDF before 1.18.0 has a heap based buffer over-write when parsing JBIG2 files allowing attackers to cause a denial of service.
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 confidenceArtifex MuPDF before version 1.18.0 contains a heap-based buffer overflow vulnerability when parsing JBIG2 image files. This memory corruption issue occurs during JBIG2 decode operations and can be triggered by a specially crafted JBIG2 file, leading to denial of service through application crash.
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
Debian LinuxOperating system
= 9.0= 10.0
FedoraOperating system
= 32= 33< 1.18.0CVSS 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
- Local
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/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 installed MuPDF versionRun 'mupdf --version' or check the package manager (dpkg -l mupdf or rpm -q mupdf)Affected if Version is below 1.18.0
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Check if MuPDF is linked to JBIG2 librariesRun 'ldd $(which mupdf)' or check the binary for jbig2dec library linkageAffected if JBIG2 decoding support is present in the MuPDF build
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Determine if JBIG2 image processing is in useReview application logs or user workflows for .jbig2 or JBIG2-encoded file processingAffected if The system processes JBIG2 image files, especially from untrusted sources
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Identify applications using MuPDF libraryCheck for applications that link to libmupdf (ldconfig -p | grep mupdf)Affected if Any dependent applications use the vulnerable MuPDF library version
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Review PDF/PS document processing pipelinesInspect document conversion workflows or PDF viewers that may render embedded JBIG2 imagesAffected if Documents containing JBIG2 images are being rendered
You are affected if MuPDF version is below 1.18.0 and your environment processes JBIG2 image files, as the heap overflow occurs during JBIG2 decode operations.
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.
From vendor data1.18.0
Upgrade MuPDF to version 1.18.0 or later to obtain the patched version. If immediate upgrading is not feasible, restrict untrusted JBIG2 file processing and implement input validation for JBIG2 files before rendering.
Fix this in Debian Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-26519 — 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-2020-26519 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
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