CVE-2026-45696

/// Technical description

OpenEXR is the reference implementation and specification for the EXR image format, widely used in the motion picture industry. In versions 3.4.0 through 3.4.11, the HTJ2K (High-Throughput JPEG 2000) decoder, ht_undo_impl() in OpenEXRCore is vulnerable to a heap-buffer-overflow READ. The ht_undo_imp function copies decoded pixels out of a per-line OpenJPH buffer using the EXR channel's declared width as the iteration count. The codestream embedded in the EXR chunk can declare different (smaller) tile/line dimensions than the EXR header advertises, but ht_undo_impl() does not validate this — it pulls width 32-bit samples from cur_line->i32[] without checking the OpenJPH line buffer's actual length. A crafted EXR file produces a 4-byte heap-buffer-overflow READ immediately after a buffer allocated by ojph::local::codestream::finalize_alloc(). The bug is reachable through the standard scanline-decode entry point used by every consumer of exr_decoding_run/Imf::checkOpenEXRFile, including

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References