CVE-2026-42217
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 · uneditedOpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From versions 3.0.0 to before 3.2.9, 3.3.0 to before 3.3.11, and 3.4.0 to before 3.4.11, readVariableLengthInteger() decodes a variable-length integer from untrusted EXR input without bounding the shift count. After enough continuation bytes, the code executes a left shift by 70 on a 64-bit value, which is undefined behavior. This issue has been patched in versions 3.2.9, 3.3.11, and 3.4.11.
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 confidenceOpenEXR's readVariableLengthInteger() function lacks bounds checking on shift counts when decoding variable-length integers from EXR files. A malicious EXR file can trigger a left shift by 70 on a 64-bit value, causing undefined behavior that could potentially be exploited for code execution or cause denial of service.
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>= 3.0.0, < 3.2.9>= 3.3.0, < 3.3.11>= 3.4.0, < 3.4.11CVSS 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 OpenEXR versionRun 'openexr-config --version' or check your package manager for openexr version (dpkg -l | grep openexr, rpm -qa | grep openexr, or brew list openexr)Affected if Version is 3.0.0 through 3.2.8, 3.3.0 through 3.3.10, or 3.4.0 through 3.4.10
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Locate the OpenEXR library binaryFind libIex.so or libIex-3_4.so in /usr/lib, /usr/local/lib, or application bundling directory using 'find /usr -name "libIex*" 2>/dev/null'Affected if Library version falls within the affected ranges above
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Verify vulnerable function presenceCheck if the readVariableLengthInteger function exists in the binary using 'nm -C libIex.so | grep readVariableLengthInteger' or 'strings libIex.so | grep readVariableLengthInteger'Affected if Function is present and library version is in affected range
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Determine if application processes EXR filesReview application code or logs for .exr file loading, or monitor file access with 'strace -e openat your_app 2>&1 | grep -i exr' during typical operationAffected if Application loads or parses EXR files and OpenEXR library version is in affected range
You are affected if your OpenEXR library version is 3.0.0-3.2.8, 3.3.0-3.3.10, or 3.4.0-3.4.10 and your system processes EXR files.
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 · scoped3.2.93.3.113.4.11
Upgrade OpenEXR to version 3.2.9, 3.3.11, or 3.4.11 or later. Avoid processing untrusted EXR files until the patch is applied.
3.2.9, 3.3.11, or 3.4.11 (select based on major version compatibility)
- Identify the current OpenEXR version installed in your environment
- Upgrade OpenEXR to version 3.2.9, 3.3.11, or 3.4.11 (choose the version that is compatible with your dependency chain)
- For package manager installations: use your system's package manager to update (e.g., apt-get update && apt-get install libopenexr-dev, or pip install --upgrade OpenEXR, depending on your setup)
- For source builds: download the release from https://github.com/AcademySoftwareFoundation/openexr/releases and rebuild
- Verify the installed version matches one of the fixed releases
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation2.0 h
- Testing6.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-42217 — 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-2026-42217 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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- Version or environment caveats, and links to real fixes
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