CVE-2026-55371
MEDIUMDescription
OpenEXR is the reference implementation and specification for the EXR high-dynamic-range image file format, widely used in the motion picture industry. Versions 3.4.0 through 3.4.12 contain a NULL pointer dereference in the OpenEXRCore function exr_attr_set_bytes(). The public setter validates the top-level exr_attr_bytes_t value pointer but does not verify that the nested type_hint pointer is non-NULL when hint_length is greater than zero. When a caller supplies a positive hint_length together with a NULL type_hint, exr_attr_bytes_create() allocates a destination type-hint buffer and then copies from the NULL source pointer, causing a deterministic crash. The flaw is reachable through the public OpenEXRCore C API and results in a denial of service. The issue is fixed in version 3.4.13.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v4 Vector
Exploitability
Impact
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Exploit Intelligence
Low risk: more likely to be exploited than 2% of all known CVEs.
References
Related Vulnerabilities
Other CWE-20 (Improper Input Validation) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2024-3400 | Critical | 10.0 | 100% | KEV + Ransom | - |
| CVE-2021-45105 | Medium | 5.9 | 100% | - | Fix |
| CVE-2021-44228 | Critical | 10.0 | 100% | KEV + Ransom | Fix |
| CVE-2021-21985 | Critical | 9.8 | 100% | KEV + Ransom | Fix |
| CVE-2020-3452 | High | 7.5 | 100% | KEV | Fix |
| CVE-2018-7600 | Critical | 9.8 | 100% | KEV + Ransom | Fix |
Common questions
How do I fix CVE-2026-55371?
Upgrade openexr on debian unstable to 3.4.14-0.1 or later.
Is CVE-2026-55371 being actively exploited?
Not that we know of. CVE-2026-55371 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.12% is the estimated probability that it will be exploited in the next 30 days. That is higher than 2% of all scored CVEs.
How severe is CVE-2026-55371?
CVE-2026-55371 has a CVSS v4 base score of 6.9, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-55371 affect?
Published advisories record a fix for openexr (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2026-55371
Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-08-25.