openexr — security advisory

{
  "id": "30916f731c045022d6d75895da375a291e4b5dafb3207cab676597e0351a6b7a",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-39886",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-39886",
    "summary": "OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. Versions 3.4.0 through 3.4.9 have a signed integer overflow vulnerability in OpenEXR's HTJ2K (High-Throughput JPEG 2000) decompression path. The `ht_undo_impl()` function in `src/lib/OpenEXRCore/internal_ht.cpp` accumulates a bytes-per-line value (`bpl`) using a 32-bit signed integer with no overflow guard. A crafted EXR file with 16,385 FLOAT channels at the HTJ2K maximum width of 32,767 causes `bpl` to overflow `INT_MAX`, producing undefined behavior confirmed by UBSan. On an allocator-permissive host where the required ~64 GB allocation succeeds, the wrapped negative `bpl` value would subsequently be used as a per-scanline pointer advance, which would produce a heap out-of-bounds write. On a memory-constrained host, the allocation fails before `ht_undo_impl()` is entered. This is the second distinct integer overflow in `ht_undo_impl()`. CVE-2026-34545 addressed a different overflow in the same function — the `int16_t p` pixel-loop counter at line ~302 that overflows when iterating over channels whose `width` exceeds 32,767. The CVE-2026-34545 fix did not touch the `int bpl` accumulator at line 211, which is the subject of this advisory. The `bpl` accumulator was also not addressed by any of the 8 advisories in the 2026-04-05 v3.4.9 release batch. This finding is structurally identical to CVE-2026-34588 (PIZ `wcount*nx` overflow in",
    "evidence": "osv:UBUNTU-CVE-2026-39886",
    "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-2026-39886",
      "aliases": [
        "UBUNTU-CVE-2026-39886"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
        },
        {
          "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-2026-39886.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": "2026-10-17T12:58:13.936821325Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-39886"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-39886",
        "https://www.cve.org/CVERecord?id=CVE-2026-39886"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-39886",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 358394,
  "published_at": "2026-04-21T02:16:00+00:00"
}