Raw vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/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:XSummary
CVE-2026-40244 is a high-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Openexr Openexr. Its CVSS base score is 8.4 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 35th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-40244 is an integer overflow vulnerability (CWE-190) in the OpenEXR library, which provides the specification and reference implementation for the EXR image file format used in the motion picture industry. The flaw occurs in `internal_dwa_compressor.h` at line 1722, where the calculation `curc->width * curc->height` is performed using int32 arithmetic without a cast to `size_t`, potentially leading to overflows. It affects OpenEXR versions 3.4.0 through 3.4.9, 3.3.0 through 3.3.9, and 3.2.0 through 3.2.7. This issue follows the same overflow pattern addressed in the CVE-2026-34589 fixes but was overlooked in that batch.
The vulnerability has a CVSS v3.1 base score of 7.1 (AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H), indicating local access is required with low attack complexity, no privileges, and user interaction. An attacker can exploit it by crafting a malicious EXR file that, when opened by a local user in an application linked to a vulnerable OpenEXR version, triggers the overflow during DWA compression handling. Successful exploitation results in high integrity and availability impacts, such as application crashes or memory corruption, but no confidentiality loss.
Mitigation involves upgrading to the fixed releases: OpenEXR 3.4.10, 3.3.10, or 3.2.8, as detailed in the GitHub release notes and the security advisory GHSA-j526-66f6-fxhx. Practitioners should audit dependencies in image processing software, such as those in VFX pipelines or graphics applications, for vulnerable OpenEXR versions and apply patches promptly.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-24046
Vulnerability Data
OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. In versions 3.4.0 through 3.4.9, 3.3.0 through 3.3.9, and 3.2.0 through 3.2.7, `internal_dwa_compressor.h:1722` performs `curc->width * curc->height` in `int32`…
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arithmetic without a `(size_t)` cast. This is the same overflow pattern fixed in other locations by the recent CVE-2026-34589 batch, but this line was missed. Versions 3.4.10, 3.3.10, and 3.2.8 contain a fix that addresses `internal_dwa_compressor.h:1722`.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.2.6
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (static analysis, fuzzing, unit tests) directly finds integer overflow defects before deployment.
Secure engineering principles require use of safe arithmetic constructs or language features that structurally eliminate integer overflow during calculation.
Input validation enforces bounds on values before arithmetic, stopping the conditions that trigger overflow or wraparound.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require use of safe arithmetic, bounds checks, and testing that prevent integer overflows.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development can detect integer overflows before release.
Secure SDLC mandates input validation and arithmetic checks that prevent integer overflows.
Application security requirements include bounds checking and safe arithmetic to avoid overflow conditions.
Secure architecture principles require defensive coding patterns that mitigate integer wraparound risks.
Secure coding standards explicitly forbid unsafe integer operations and mandate overflow-safe constructs.