Signed to Unsigned Conversion Error in OpenEXR - CVE-2026-26981
Published: April 8, 2026
Vulnerability identifier: #VU125324
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-26981
CWE-ID: CWE-195
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to signed to unsigned conversion error in the istream_nonparallel_read function in ImfContextInit.cpp when parsing a malformed EXR file through a memory-mapped IStream. A remote attacker can supply a specially crafted EXR file to cause a denial of service.
User interaction is required to open the crafted file. Only applications using an IStream implementation where isMemoryMapped() returns true are vulnerable.
Affected software
OpenEXR
Fedora
mingw-openexr
Fedora
mingw-openexr
How to mitigate CVE-2026-26981
Install security update from vendor's website.
OpenEXR - addressed in versions 3.3.7, 3.4.5
mingw-openexr - addressed in versions 3.3.8-1.fc42, 3.3.8-1.fc43, 3.4.6-1.fc44
mingw-openexr - addressed in versions 3.3.8-1.fc42, 3.3.8-1.fc43, 3.4.6-1.fc44