PYSEC-2026-2849 OpenEXR has heap-buffer-overflow via signed integer underflow in ImfContextInit.cpp

Summary A heap-buffer-overflow OOB read occurs in the istreamnonparallelread function in ImfContextInit.cpp when parsing a malformed EXR file through a memory-mapped IStream. A signed integer subtraction produces a negative value that is implicitly converted to sizet, resulting in a massive lengt...

GHSA-Q6VJ-WXVF-5M8C OpenEXR has heap-buffer-overflow via signed integer underflow in ImfContextInit.cpp

Summary A heap-buffer-overflow OOB read occurs in the istreamnonparallelread function in ImfContextInit.cpp when parsing a malformed EXR file through a memory-mapped IStream. A signed integer subtraction produces a negative value that is implicitly converted to sizet, resulting in a massive lengt...

CVE-2026-26981

OpenEXR CVE-2026-26981 affects 3.3.0–3.3.6 and 3.4.0–3.4.4; a heap-buffer-overflow (OOB read) occurs in istream_nonparallel_read in ImfContextInit.cpp when parsing a malformed EXR via a memory-mapped IStream. A signed integer subtraction becomes a negative value that is implicitly cast to size_t,...