Cyber Resilience

CVE-2026-42217

MediumPublic PoC

Published: 07 May 2026

Published
07 May 2026
Modified
08 May 2026
KEV Added
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Patch
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CVSS Score v4 6.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/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 0.0039 31.2th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-42217 is a medium-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Openexr Openexr. Its CVSS base score is 6.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 31.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From versions 3.0.0 to before 3.2.9, 3.3.0 to before 3.3.11, and 3.4.0 to before 3.4.11, readVariableLengthInteger() decodes a variable-length…

more

integer from untrusted EXR input without bounding the shift count. After enough continuation bytes, the code executes a left shift by 70 on a 64-bit value, which is undefined behavior. This issue has been patched in versions 3.2.9, 3.3.11, and 3.4.11.

CWE(s)
CWE-190

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

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.
attack.mitre.org →
T1204.002 Malicious File Execution
An adversary may rely upon a user opening a malicious file in order to gain execution.
attack.mitre.org →
Why these techniques?

Integer overflow/UB in untrusted EXR file parsing enables RCE via malicious image files (T1204.002) or against public-facing apps processing such input (T1190).

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

Affected Assets

openexr
openexr
3.0.0 — 3.2.9 · 3.3.0 — 3.3.11 · 3.4.0 — 3.4.11

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References