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openexr — security advisory

Type: advisorySources: OSVAdvisory ID: UBUNTU-CVE-2026-34378

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From 3.4.0 to before 3.4.9, a missing bounds check on the dataWindow attribute in EXR file headers allows an attacker to trigger a signed integer overflow in generic_unpack(). By setting dataWindow.min.x to a large negative value, OpenEXRCore computes an enormous image width, which is later used in a signed integer multiplication that overflows, causing the process to terminate with SIGILL via UBSan. This vulnerability is fixed in 3.4.9.

Products
openexr
Affected versions
3.1.13-2build1, 3.4.6+ds-4ubuntu3
Fixed versions
Not specified
CVEs
CVE-2026-34378
Confirmed fixed CVEs
Not specified
Updated in this feed
31 Oct 2026, 03:00 UTC · Revision 1

Source evidence

UBUNTU-CVE-2026-34378

core-osv · Original source

Published 6 Apr 2026, 16:16 UTC

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From 3.4.0 to before 3.4.9, a missing bounds check on the dataWindow attribute in EXR file headers allows an attacker to trigger a signed integer overflow in generic_unpack(). By setting dataWindow.min.x to a large negative value, OpenEXRCore computes an enormous image width, which is later used in a signed integer multiplication that overflows, causing the process to terminate with SIGILL via UBSan. This vulnerability is fixed in 3.4.9.

osv:UBUNTU-CVE-2026-34378

openexr

Fixed versions: Not specified

Complete source record
{
  "id": "116815c3d093d9185b5def9398e13c5166789059c5b3eab15beaf2d066086ce2",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-34378",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-34378",
    "summary": "OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From 3.4.0 to before 3.4.9, a missing bounds check on the dataWindow attribute in EXR file headers allows an attacker to trigger a signed integer overflow in generic_unpack(). By setting dataWindow.min.x to a large negative value, OpenEXRCore computes an enormous image width, which is later used in a signed integer multiplication that overflows, causing the process to terminate with SIGILL via UBSan. This vulnerability is fixed in 3.4.9.",
    "evidence": "osv:UBUNTU-CVE-2026-34378",
    "products": [
      {
        "name": {
          "value": "openexr",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "3.1.13-2build1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "3.4.6+ds-4ubuntu3",
            "evidence": "/affected/0/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "UBUNTU-CVE-2026-34378",
      "aliases": [
        "UBUNTU-CVE-2026-34378"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"
        },
        {
          "type": "Ubuntu",
          "score": "medium"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "openexr",
            "purl": "pkg:deb/ubuntu/openexr?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "3.1.13-2build1",
            "3.4.6+ds-4ubuntu3"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34378.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "libopenexr-3-4-33",
                "binary_version": "3.4.6+ds-4ubuntu3"
              },
              {
                "binary_name": "openexr",
                "binary_version": "3.4.6+ds-4ubuntu3"
              }
            ]
          }
        }
      ],
      "modified": "2026-10-17T13:00:01.050597326Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-34378"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-34378",
        "https://www.cve.org/CVERecord?id=CVE-2026-34378",
        "https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-v76p-4qvv-vh4g",
        "https://github.com/AcademySoftwareFoundation/openexr/pull/2321",
        "https://github.com/AcademySoftwareFoundation/openexr/commit/088859fb6199e56824c4c9ed60afc825261bfea9",
        "https://github.com/AcademySoftwareFoundation/openexr/commit/7a1c64ca74d12bf5f64a912d4e12a651689f8652",
        "https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.4.9"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-34378",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 360130,
  "published_at": "2026-04-06T16:16:00+00:00"
}