Memory corruption via wrapped PIZ wavelet pointer
Published Apr 6, 2026 · Updated Apr 6, 2026
Integer overflow in OpenEXR allows attackers to corrupt process memory through PIZ decompression of a crafted EXR file. internal_exr_undo_piz() multiplies attacker-controlled channel dimensions and sample counts in signed 32-bit arithmetic, wraps the wavelet buffer pointer, and decodes the next channel out of bounds. Reachability requires a local process or downstream application to decode the file; the in-place wavelet routine reads and writes outside the buffer, causing a crash or memory corruption.
Summary
What happened
Integer overflow in OpenEXR allows attackers to corrupt process memory through PIZ decompression of a crafted EXR file. internal_exr_undo_piz() multiplies attacker-controlled channel dimensions and sample counts in signed 32-bit arithmetic, wraps the wavelet buffer pointer, and decodes the next channel out of bounds. Reachability requires a local process or downstream application to decode the file; the in-place wavelet routine reads and writes outside the buffer, causing a crash or memory corruption.
The record
- CVE
- CVE-2026-34588
- Published
- Apr 6, 2026
- Updated
- Apr 6, 2026
- Vendor
- Academy Software Foundation
- Product
- OpenEXR
- Classifications
- CWE-190, CWE-787, CWE-125
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 6, 2026CVE publishedPublication date reported by the CVE source.
- Apr 6, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 3.1.0, <= 3.1.13
- Affected versionversion=>= 3.2.0, < 3.2.7
- Affected versionversion=>= 3.3.0, < 3.3.9
- Affected versionversion=>= 3.4.0, < 3.4.9
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- piz_scanline_redzone EXR reproducerproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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