CVE-2026-34379
HighCVSS 7.1Exploitation Probability (EPSS)
Low risk20th percentile - higher than 20% of all known CVEs
Summary
In OpenEXR versions 3.2.0 through 3.2.7, 3.3.9, and 3.4.9, a misaligned memory write vulnerability exists in LossyDctDecoder_execute(). When decoding a DWA/DWAB-compressed EXR file with a FLOAT channel, an unaligned row pointer is cast to float*, causing undefined behavior and crashes on alignment-sensitive architectures (ARM, RISC-V).
Risk Assessment
An attacker can craft a malicious EXR file causing application crashes (DoS) on systems using OpenEXR. On x86, the issue is silently tolerated at runtime but remains exploitable via compiler optimizations assuming aligned access.
Recommendation
Upgrade OpenEXR to version 3.2.7, 3.3.9, or 3.4.9 immediately, depending on your release branch.
Other vulnerabilities in OpenEXR
See all- CVE-2017-12596High
In OpenEXR 2.2.0, a crafted image causes a heap-based buffer over-read in the hufDecode function in IlmImf/ImfHuf.cpp during exrmaketiled execution; it may result in denial of service or possibly unspecified other impact.
- CVE-2017-9115High
In OpenEXR 2.2.0, an invalid write of size 2 in the = operator function in half.h could cause the application to crash or execute arbitrary code.
- CVE-2017-9113High
In OpenEXR 2.2.0, an invalid write of size 1 in the bufferedReadPixels function in ImfInputFile.cpp could cause the application to crash or execute arbitrary code.
- CVE-2017-9111High
In OpenEXR 2.2.0, an invalid write of size 8 in the storeSSE function in ImfOptimizedPixelReading.h could cause the application to crash or execute arbitrary code.
- CVE-2026-42217Critical
OpenEXR versions from 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 have an issue with the readVariableLengthInteger() function that 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, leading to undefined behavior.
- CVE-2026-42216Critical
In OpenEXR 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, a vulnerability exists in the IDManifest::init() function. When reconstructing strings from a prefix-compressed representation, the code reads bytes without verifying that the current string has at least two bytes, potentially causing an out-of-bounds read.
- CVE-2026-68515High
OpenEXR before versions 3.2.11, 3.3.13, and 3.4.14 contains a vulnerability in the exrmultiview utility that can write past a heap allocation when combining two attacker-supplied, individually valid scanline EXR files whose union dataWindow is not aligned to one view's channel subsampling. This leads to a heap out-of-bounds write.
- CVE-2026-68514Medium
PyOpenEXR versions 3.3.0-3.3.12 and 3.4.0-3.4.13 have a heap out-of-bounds write vulnerability when reading a crafted deep scanline EXR file. A specially crafted file with a 'left' channel and layer-prefixed RGB channels can cause a buffer overflow and crash.
- CVE-2026-68513High
OpenEXR versions 3.3.0 through 3.3.12 and 3.4.0 through 3.4.13 contain a heap buffer overflow in PyOpenEXR triggered by a channel-name key collision between literal and prefixed RGB channels. A crafted EXR file can cause an out-of-bounds write in a NumPy array during pixel decoding.
- CVE-2026-59981High
OpenEXR versions through 3.2.10, 3.3.0 through 3.3.12, and 3.4.0 through 3.4.13 contain a vulnerability in the OpenEXRUtil library that returns an out-of-bounds pointer from the SampleCountChannel::row() API for deep images with a non-zero dataWindow origin. This can lead to an out-of-bounds read, potentially causing a process crash or disclosure of memory data.
Original NVD description (English source)
OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From 3.2.0 to before 3.2.7, 3.3.9, and 3.4.9, a misaligned memory write vulnerability exists in LossyDctDecoder_execute() in src/lib/OpenEXRCore/internal_dwa_decoder.h:749. When decoding a DWA or DWAB-compressed EXR file containing a FLOAT-type channel, the decoder performs an in-place HALF→FLOAT conversion by casting an unaligned uint8_t * row pointer to float * and writing through it. Because the row buffer may not be 4-byte aligned, this constitutes undefined behavior under the C standard and crashes immediately on architectures that enforce alignment (ARM, RISC-V, etc.). On x86 it is silently tolerated at runtime but remains exploitable via compiler optimizations that assume aligned access. This vulnerability is fixed in 3.2.7, 3.3.9, and 3.4.9.