id: PYSEC-2026-1749
published: "2026-07-07T16:02:59.949434Z"
modified: "2026-07-07T16:02:59.949434Z"
aliases:
- CVE-2025-48074
- GHSA-x22w-82jp-8rvf
summary: OpenEXR Out-Of-Memory via Unbounded File Header Values
details: "### Summary\nThe OpenEXR file format defines many information about the final image inside of the file header, such as the size of data/display window.\n\nThe application trusts the value of `dataWindow` size provided in the header of the input file, and performs computations based on this value.\n\nThis may result in unintended behaviors, such as excessively large number of iterations and/or huge memory allocations.\n\n\n### Details\nA concrete example of this issue is present in the function `readScanline()` in `ImfCheckFile.cpp` at line 235, that performs a for-loop using the `dataWindow min.y` and `max.y` coordinates that can be arbitrarily large.\n\n```cpp\nin.setFrameBuffer (i);\n\nint step = 1;\n\n//\n// try reading scanlines. Continue reading scanlines\n// even if an exception is encountered\n//\nfor (int y = dw.min.y; y <= dw.max.y; y += step) // <-- THIS LOOP IS EXCESSIVE BECAUSE OF DW.MAX\n{\n    try\n    {\n        in.readPixels (y);\n    }\n    catch (...)\n    {\n        threw = true;\n\n        //\n        // in reduceTime mode, fail immediately - the file is corrupt\n        //\n        if (reduceTime) { return threw; }\n    }\n}\n```\n\nAnother example occurs in the `EnvmapImage::resize` function that in turn calls `Array2D<T>::resizeEraseUnsafe` passing the `dataWindow` X and Y coordinates and perform a huge allocation.\n\nOn some system, the allocator will simply return `std::bad_alloc` and crash. On other systems such as macOS, the allocator will happily continue with a \"small\" pre-allocation and allocate further memory whenever it is accessed.\nThis is the case with the `EnvmapImage::clear` function that is called right after and fills the image RGB values with zeros, allocating tens of Gigabytes.\n\n### PoC\n\nNOTE: please download the `oom_crash.exr` file via the following link:\n \nhttps://github.com/ShielderSec/poc/tree/main/CVE-2025-48074\n\n1. Compile the `exrcheck` binary in a macOS or GNU/Linux machine with ASAN.\n2. Open the `oom_crash.exr` file with the following command:\n\n```\nexrcheck oom_crash.exr\n```\n\n3. Notice that `exrenvmap`/`exrcheck` crashes with ASAN stack-trace.\n\n### Impact\nAn attacker could cause a denial of service by stalling the application or exhaust memory by stalling the application in a loop which contains a memory leakage."
affected:
- package:
    name: openexr
    ecosystem: PyPI
    purl: pkg:pypi/openexr
  ranges:
  - type: ECOSYSTEM
    events:
    - introduced: 3.3.2
    - fixed: 3.3.3
  versions:
  - 3.3.2
references:
- type: WEB
  url: https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-x22w-82jp-8rvf
- type: ADVISORY
  url: https://nvd.nist.gov/vuln/detail/CVE-2025-48074
- type: WEB
  url: https://github.com/AcademySoftwareFoundation/openexr/commit/2df7802a6421bf39ed73a607392f01b3c6da4e4a
- type: PACKAGE
  url: https://github.com/AcademySoftwareFoundation/openexr
- type: WEB
  url: https://github.com/ShielderSec/poc/tree/main/CVE-2025-48074
- type: PACKAGE
  url: https://pypi.org/project/openexr
- type: ADVISORY
  url: https://github.com/advisories/GHSA-x22w-82jp-8rvf
severity:
- type: CVSS_V4
  score: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N