CVE-2026-34380
OpenEXR has a signed integer overflow (undefined behavior) in undo_pxr24_impl may allow bounds-check bypass in PXR24 decompression
Description
OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From 3.2.0 to before 3.2.7, 3.3.9, and 3.4.9, a signed integer overflow exists in undo_pxr24_impl() in src/lib/OpenEXRCore/internal_pxr24.c at line 377. The expression (uint64_t)(w * 3) computes w * 3 as a signed 32-bit integer before casting to uint64_t. When w is large, this multiplication constitutes undefined behavior under the C standard. On tested builds (clang/gcc without sanitizers), two's-complement wraparound commonly occurs, and for specific values of w the wrapped result is a small positive integer, which may allow the subsequent bounds check to pass incorrectly. If the check is bypassed, the decoding loop proceeds to write pixel data through dout, potentially extending far beyond the allocated output buffer. This vulnerability is fixed in 3.2.7, 3.3.9, and 3.4.9.
INFO
Published Date :
April 6, 2026, 4:16 p.m.
Last Modified :
April 7, 2026, 7:03 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Update OpenEXR to version 3.2.7 or later.
- Update OpenEXR to version 3.3.9 or later.
- Update OpenEXR to version 3.4.9 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-34380.
| URL | Resource |
|---|---|
| https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.2.7 | Product Release Notes |
| https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.3.9 | Product Release Notes |
| https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.4.9 | Product Release Notes |
| https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-q3v8-hw4m-59w5 | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-34380 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-34380
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-34380 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-34380 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Apr. 07, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:openexr:openexr:*:*:*:*:*:*:*:* versions from (including) 3.2.0 up to (excluding) 3.2.7 *cpe:2.3:a:openexr:openexr:*:*:*:*:*:*:*:* versions from (including) 3.3.0 up to (excluding) 3.3.9 *cpe:2.3:a:openexr:openexr:*:*:*:*:*:*:*:* versions from (including) 3.4.0 up to (excluding) 3.4.9 Added Reference Type GitHub, Inc.: https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.2.7 Types: Product, Release Notes Added Reference Type GitHub, Inc.: https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.3.9 Types: Product, Release Notes Added Reference Type GitHub, Inc.: https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.4.9 Types: Product, Release Notes Added Reference Type GitHub, Inc.: https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-q3v8-hw4m-59w5 Types: Exploit, Vendor Advisory -
CVE Modified by [email protected]
Apr. 07, 2026
Action Type Old Value New Value Added Reference https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.2.7 Added Reference https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.3.9 Added Reference https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.4.9 -
New CVE Received by [email protected]
Apr. 06, 2026
Action Type Old Value New Value Added Description OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From 3.2.0 to before 3.2.7, 3.3.9, and 3.4.9, a signed integer overflow exists in undo_pxr24_impl() in src/lib/OpenEXRCore/internal_pxr24.c at line 377. The expression (uint64_t)(w * 3) computes w * 3 as a signed 32-bit integer before casting to uint64_t. When w is large, this multiplication constitutes undefined behavior under the C standard. On tested builds (clang/gcc without sanitizers), two's-complement wraparound commonly occurs, and for specific values of w the wrapped result is a small positive integer, which may allow the subsequent bounds check to pass incorrectly. If the check is bypassed, the decoding loop proceeds to write pixel data through dout, potentially extending far beyond the allocated output buffer. This vulnerability is fixed in 3.2.7, 3.3.9, and 3.4.9. Added CVSS V3.1 AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:H Added CWE CWE-787 Added CWE CWE-190 Added Reference https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-q3v8-hw4m-59w5