openexr — security advisory
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.
- Products
- openexr
- Affected versions
- 3.1.13-2, 3.1.13-2build1, 3.1.5-5.1, 3.1.5-5.1build1, 3.1.5-5.1build2, 3.1.5-5.1build3, 3.4.6+ds-4ubuntu3
- Fixed versions
- 3.1.13-2ubuntu0.26.04.1~esm1, 3.1.5-5.1ubuntu0.1~esm1
- CVEs
- CVE-2026-34380
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 02:59 UTC · Revision 1
Source evidence
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.
osv:UBUNTU-CVE-2026-34380
openexr
Fixed versions: 3.1.5-5.1ubuntu0.1~esm1
openexr
Fixed versions: Not specified
openexr
Fixed versions: Not specified
openexr
Fixed versions: 3.1.13-2ubuntu0.26.04.1~esm1
Complete source record
{
"id": "985a2f5ba98771010ef837045c11ca05d25984dc8f0da2c09d2d649c41fd5e92",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-34380",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-34380",
"summary": "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.",
"evidence": "osv:UBUNTU-CVE-2026-34380",
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"aliases": [
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"metrics": [
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"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
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"affected": [
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"versions": [
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"3.1.5-5.1build1",
"3.1.5-5.1build2",
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"ecosystem": "Ubuntu:26.10"
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"versions": [
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{
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"binary_version": "3.1.13-2ubuntu0.26.04.1~esm1"
}
],
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}
}
],
"modified": "2026-10-17T13:00:00.565326401Z",
"provider": "osv",
"upstream": [
"CVE-2026-34380"
],
"references": [
"https://ubuntu.com/security/CVE-2026-34380",
"https://www.cve.org/CVERecord?id=CVE-2026-34380",
"https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-q3v8-hw4m-59w5",
"https://github.com/AcademySoftwareFoundation/openexr/pull/2323",
"https://github.com/AcademySoftwareFoundation/openexr/commit/f5beec2bd8636102e74460a0b624d3e26efc546f",
"https://github.com/AcademySoftwareFoundation/openexr/commit/b2cebfa1c68e76cb2048ac1c1fbf1b50d196ff9d",
"https://github.com/AcademySoftwareFoundation/openexr/commit/a5e5a2eba975b57f77e1c6b6d22ecc49553624e2",
"https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.2.7",
"https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.3.9",
"https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.4.9",
"https://ubuntu.com/security/notices/USN-8259-1"
]
},
"related_cves": [
{
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"evidence": "/upstream"
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],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 360107,
"published_at": "2026-04-06T16:16:00+00:00"
}