CVE-2026-39886
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk23th percentile - higher than 23% of all known CVEs
Summary
OpenEXR versions 3.4.0 through 3.4.9 contain a signed 32-bit integer overflow in the ht_undo_impl() function of the HTJ2K decompression path. A crafted EXR file with 16,385 FLOAT channels at the HTJ2K maximum width of 32,767 overflows the bpl accumulator beyond INT_MAX, causing undefined behavior and potentially a heap out-of-bounds write on allocator-permissive hosts.
Risk Assessment
The vulnerability can cause memory corruption (heap out-of-bounds write) when processing a malicious EXR file, risking application crashes or potential code execution. Risk applies to systems processing untrusted EXR files, especially with large available memory.
Recommendation
Update OpenEXR to version 3.4.10, which contains the remediation in internal_ht.cpp. Until patched, avoid processing untrusted EXR files in production environments.
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. Versions 3.4.0 through 3.4.9 have a signed integer overflow vulnerability in OpenEXR's HTJ2K (High-Throughput JPEG 2000) decompression path. The `ht_undo_impl()` function in `src/lib/OpenEXRCore/internal_ht.cpp` accumulates a bytes-per-line value (`bpl`) using a 32-bit signed integer with no overflow guard. A crafted EXR file with 16,385 FLOAT channels at the HTJ2K maximum width of 32,767 causes `bpl` to overflow `INT_MAX`, producing undefined behavior confirmed by UBSan. On an allocator-permissive host where the required ~64 GB allocation succeeds, the wrapped negative `bpl` value would subsequently be used as a per-scanline pointer advance, which would produce a heap out-of-bounds write. On a memory-constrained host, the allocation fails before `ht_undo_impl()` is entered. This is the second distinct integer overflow in `ht_undo_impl()`. CVE-2026-34545 addressed a different overflow in the same function — the `int16_t p` pixel-loop counter at line ~302 that overflows when iterating over channels whose `width` exceeds 32,767. The CVE-2026-34545 fix did not touch the `int bpl` accumulator at line 211, which is the subject of this advisory. The `bpl` accumulator was also not addressed by any of the 8 advisories in the 2026-04-05 v3.4.9 release batch. This finding is structurally identical to CVE-2026-34588 (PIZ `wcount*nx` overflow in `internal_piz.c`) and should be remediated with the same pattern. The CVE-2026-34588 fix did not touch `internal_ht.cpp`. Version 3.4.10 contains a remediation that addresses the vulnerability in `internal_ht.cpp`.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS