Cyber Resilience

CVE-2026-34544

Memory Safety in Openexr 3.2.0 – 3.2.7

Public PoCMemory Safety
Published
01 April 2026
Modified
07 April 2026
Patch / advisory
CVSS Score v4 8.4
Click a component to see what it means
Raw vectorCVSS: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:X
EPSS Score 0.0024 16th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-34544 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 16th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — 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-2026-34544 is an out-of-bounds write vulnerability in the OpenEXR library, which provides the specification and reference implementation for the EXR file format used in the motion picture industry for image storage. The issue affects versions 3.4.0 through 3.4.7 and is triggered by a crafted B44 or B44A EXR file processed via the exr_decoding_run() function. It is classified under CWE-190 (Integer Overflow or Wraparound) and CWE-787 (Out-of-bounds Write), with a CVSS v3.1 base score of 7.3 (AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H).

A local attacker with low privileges can exploit this vulnerability by tricking a user into decoding a malicious EXR file in an affected application. Successful exploitation typically results in an immediate application crash, but depending on memory layout, it may corrupt adjacent heap allocations, potentially enabling arbitrary code execution, data tampering, or further compromise given the high confidentiality, integrity, and availability impacts.

The vulnerability has been addressed in OpenEXR version 3.4.8, as detailed in the project's security advisory (GHSA-h762-rhv3-h25v), release notes, and the patching commit (35e7aa35e22c1975606be86e859f31cc1fc598ee). Security practitioners should update to version 3.4.8 or later and validate EXR file inputs in applications relying on OpenEXR decoding.

EU & UK References

Vulnerability Data

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 3.4.8, a crafted B44 or B44A EXR file can cause an out-of-bounds write…

more

in any application that decodes it via exr_decoding_run(). Consequences range from immediate crash (most likely) to corruption of adjacent heap allocations (layout-dependent). This issue has been patched in version 3.4.8.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-5841Same product: Openexr Openexr
CVE-2023-39125Shared CWE-190, CWE-787
CVE-2024-20016Shared CWE-190, CWE-787
CVE-2023-33032Shared CWE-190, CWE-787
CVE-2024-32913Shared CWE-190, CWE-787
CVE-2023-47212Shared CWE-190, CWE-787
CVE-2024-47537Shared CWE-190, CWE-787
CVE-2023-22666Shared CWE-190, CWE-787
CVE-2023-45681Shared CWE-190, CWE-787
CVE-2022-23943Shared CWE-190, CWE-787

Affected Assets

openexr
openexr
3.2.0 — 3.2.7 · 3.3.0 — 3.3.9 · 3.4.0 — 3.4.8

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • 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.

Requiring documented secure-development standards and tools can mandate bounds-checked coding practices that avoid the weakness.

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.

Memory-protection mechanisms limit the exploitability and blast radius of a successful out-of-bounds write.

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.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require use of safe arithmetic, bounds checks, and testing that prevent integer overflows.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover out-of-bounds write flaws so they can be remediated.

PR.PS-02 partial match
prevents

Patching or replacing vulnerable software directly eliminates known instances of this coding weakness.

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.

finds

Security testing in development can detect integer overflows before release.

prevents

Secure SDLC mandates input validation and arithmetic checks that prevent integer overflows.

degrades

Application security requirements include bounds checking and safe arithmetic to avoid overflow conditions.

degrades

Secure architecture principles require defensive coding patterns that mitigate integer wraparound risks.

prevents

Secure coding standards explicitly forbid unsafe integer operations and mandate overflow-safe constructs.

prevents

Change management can enforce review gates that catch unsafe memory operations before deployment.

References