How to Fix CVE-2026-34545: openexr (Bundle Sibling)

*By Sai Kiran Pandrala*

Last verified: 2026-05-25

CVE-2026-34545 is a sibling vulnerability in the same Academysoftwarefoundation openexr advisory bundle as CVE-2026-34378. The same patched build closes every CVE in the bundle, so the remediation procedure for CVE-2026-34545 matches the primary write-up.

What is different about CVE-2026-34545?

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From version 3.4.0 to before version 3.4.7, an attacker providing a crafted .exr file with HTJ2K compression and a channel width of 32768 can write controlled data beyond the output heap buffer in any application that decodes EXR images. The write primitive is 2 bytes per overflow iteration or 4 bytes (by another path), repeating for each additional...

Impact is consistent with the bundle: remote code execution on the affected system. The patched build closes every code path in the advisory in one update.

How to fix CVE-2026-34545

Apply the patched build per the primary write-up: How to Fix CVE-2026-34378.

For a quick check, confirm the running version of openexr:

# Confirm the installed version via your package manager
dpkg -l | grep -i openexr   # Debian/Ubuntu
rpm -qa | grep -i openexr   # RHEL/CentOS/Rocky

Frequently asked questions

Is CVE-2026-34545 being actively exploited?

Not at the time of writing. It is not listed in CISA's Known Exploited Vulnerabilities catalog. That status can change, so monitor the vendor advisory and the KEV catalog if the system is exposed.

How severe is CVE-2026-34545?

CVSS rates it 8.4 (High). Use that score to set your patch priority alongside the other items in your queue.

Do I have to take openexr offline to apply the patch?

It depends on the deployment. High-availability or clustered installs can usually patch one node at a time with no full outage. Standalone installs typically need a short restart. Always follow the vendor's documented upgrade steps.

What if my vulnerability scanner still flags CVE-2026-34545 after I patch?

Re-run the scan after a service restart, then confirm the scanner's plugin set is up to date. Some scanners detect by banner version only and lag the official fix metadata by a release.

References

• Official vendor advisory: https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-ghfj-fx47-wg97
• NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2026-34545
• CISA KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog
• Primary write-up: How to Fix CVE-2026-34378

*Written by Sai Kiran Pandrala. Last verified 2026-05-25. Part of the Academysoftwarefoundation openexr advisory bundle. Full procedure at how-to-fix-cve-2026-34378.*