UBUNTU-CVE-2026-34379 (CVE-2026-34379)

Vulnerability from osv_ubuntu – Published: 2026-04-06 16:16 – Updated: 2026-10-17 09:40 – Source website
VLAI
Details

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.

Severity
7.1 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H
7.1 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "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"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.10",
        "name": "openexr",
        "purl": "pkg:deb/ubuntu/openexr@3.4.6+ds-4ubuntu3?arch=source\u0026distro=stonking"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.1.13-2build1",
        "3.4.6+ds-4ubuntu3"
      ]
    }
  ],
  "aliases": [],
  "details": "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\u2192FLOAT 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.",
  "id": "UBUNTU-CVE-2026-34379",
  "modified": "2026-10-17T09:40:52Z",
  "published": "2026-04-06T16:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-34379"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-34379"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-w88v-vqhq-5p24"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/AcademySoftwareFoundation/openexr/pull/2324"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/AcademySoftwareFoundation/openexr/commit/3ad9b29430f9c2599dad113e1efe619a6ec7ba67"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/AcademySoftwareFoundation/openexr/commit/d32ffe9d3727c0474b63e91556baf61ced3d89e0"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/AcademySoftwareFoundation/openexr/commit/76af7d7508819a477f2cbce808ee975da8053ce3"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.2.7"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.3.9"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.4.9"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "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": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-34379"
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON

Loading timeline…




    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.