openexr — security advisory

{
  "id": "715a2496e711742005c456dc2c7c404b9f07a4867cfd3e8c4c61042f76ed4694",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-34379",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-34379",
    "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 misaligned memory write vulnerability exists in LossyDctDecoder_execute() in src/lib/OpenEXRCore/internal_dwa_decoder.h:749. When decoding a DWA or DWAB-compressed EXR file containing a FLOAT-type channel, the decoder performs an in-place HALF→FLOAT conversion by casting an unaligned uint8_t * row pointer to float * and writing through it. Because the row buffer may not be 4-byte aligned, this constitutes undefined behavior under the C standard and crashes immediately on architectures that enforce alignment (ARM, RISC-V, etc.). On x86 it is silently tolerated at runtime but remains exploitable via compiler optimizations that assume aligned access. This vulnerability is fixed in 3.2.7, 3.3.9, and 3.4.9.",
    "evidence": "osv:UBUNTU-CVE-2026-34379",
    "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": "high",
    "structured": {
      "id": "UBUNTU-CVE-2026-34379",
      "aliases": [
        "UBUNTU-CVE-2026-34379"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H"
        },
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/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-2026-34379.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": "2026-10-17T13:00:00.842697731Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-34379"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-34379",
        "https://www.cve.org/CVERecord?id=CVE-2026-34379",
        "https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-w88v-vqhq-5p24",
        "https://github.com/AcademySoftwareFoundation/openexr/pull/2324",
        "https://github.com/AcademySoftwareFoundation/openexr/commit/3ad9b29430f9c2599dad113e1efe619a6ec7ba67",
        "https://github.com/AcademySoftwareFoundation/openexr/commit/d32ffe9d3727c0474b63e91556baf61ced3d89e0",
        "https://github.com/AcademySoftwareFoundation/openexr/commit/76af7d7508819a477f2cbce808ee975da8053ce3",
        "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"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-34379",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 360121,
  "published_at": "2026-04-06T16:16:00+00:00"
}