CVE-2026-34378
MediumCVSS 6.5Exploitation Probability (EPSS)
Low risk18th percentile - higher than 18% of all known CVEs
Summary
OpenEXR from 3.4.0 to before 3.4.9 has a missing bounds check on the dataWindow attribute in EXR file headers, allowing an attacker to trigger a signed integer overflow in generic_unpack(). Setting dataWindow.min.x to a large negative value causes an enormous image width and an overflowing multiplication, terminating the process with SIGILL via UBSan. This is fixed in 3.4.9.
Risk Assessment
A crafted EXR file can crash the image-processing process, leading to denial of service. In some configurations, it may also lead to further memory-related impacts.
Recommendation
Upgrade OpenEXR to version 3.4.9 or later. Until patched, avoid processing untrusted EXR files.
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-2026-88384Medium
OpenEXR 3.4.14 contains a NULL Pointer Dereference in the C++ attribute parsing path. A specially crafted EXR file containing an unknown-type attribute with dataSize set to zero causes the parser to create an opaque attribute with a NULL packed_data pointer. The OpaqueAttribute constructor passes the NULL pointer to memcpy() without validating the zero-size condition, resulting in undefined behavior and process termination.
- 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.
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 3.4.0 to before 3.4.9, a missing bounds check on the dataWindow attribute in EXR file headers allows an attacker to trigger a signed integer overflow in generic_unpack(). By setting dataWindow.min.x to a large negative value, OpenEXRCore computes an enormous image width, which is later used in a signed integer multiplication that overflows, causing the process to terminate with SIGILL via UBSan. This vulnerability is fixed in 3.4.9.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

