CVE-2019-19637
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 libsixel 1.8.2. There is an integer overflow in the function sixel_decode_raw_impl at fromsixel.c.
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 confidencelibsixel 1.8.2 contains an integer overflow vulnerability in the sixel_decode_raw_impl function in fromsixel.c. This occurs when processing SIXEL image data, where arithmetic operations exceed the maximum value representable in the allocated integer type, potentially leading to heap corruption, out-of-bounds memory access, or arbitrary code execution.
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= 1.8.2CVSS 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:3.1/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 installed libsixel versionRun 'pkg-config --modversion libsixel' or check the library file version with 'strings' or 'ldd' against the binary using libsixel. Also check package manager output with 'dpkg -l libsixel' or 'rpm -qi libsixel' if installed via packages.Affected if Version is exactly 1.8.2
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Confirm libsixel library presenceLocate the libsixel shared library with 'ldconfig -p | grep sixel' or by searching for 'libsixel.so' in standard library paths like /usr/lib or /usr/local/lib.Affected if libsixel library file exists on the system
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Identify applications using libsixelSearch for binaries or applications that link against libsixel using 'ldd <binary>' on suspected applications, or check application dependencies with 'objdump -p <binary> | grep libsixel'. Common consumers include terminal emulators, image viewers, or image conversion tools.Affected if Applications linked to libsixel are in use
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Check for SIXEL image data processingReview application logs or user activity for SIXEL format image processing. SIXEL images typically have a specific header pattern. Use 'file <image>' or hex dump to check if SIXEL images are being decoded.Affected if SIXEL format images are being decoded through the vulnerable sixel_decode_raw_impl function
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Verify memory allocation patternsIf source code is available, audit calls to sixel_decode_raw_impl for unsafe width/height parameter handling. Check if user-controlled image dimensions are passed without validation before the decode call.Affected if Width and height parameters from untrusted input reach sixel_decode_raw_impl without bounds validation
The environment is affected if libsixel version 1.8.2 is installed AND applications are actively decoding SIXEL image data using the sixel_decode_raw_impl function with unvalidated dimensions.
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 dataUpgrade to a patched version of libsixel that addresses the integer overflow vulnerability in sixel_decode_raw_impl. If upgrading is not immediately possible, implement input validation to restrict decode parameters to safe ranges before processing.
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA3.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2019-19637 — 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-2019-19637 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
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