# CVE-2026-27622: OpenEXR heap out-of-bounds write in CompositeDeepScanLine

Source: https://junglewise.ai/threats/cve-2026-27622-openexr-heap-out-of-bounds-write-in-compositedeepscanline  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-03-03. Updated: 2026-06-30  
License: CC BY 4.0 with a link back

CVE-2026-27622 · Severity: high · CVSS 7.8 · Published 2026-03-03

OpenEXR is a widely used image format in the motion picture and visual effects industry for storing high-quality graphics. A vulnerability in how the software processes certain image files could allow an attacker to execute malicious code or crash applications that open a specially crafted EXR file. This could lead to the theft of sensitive data, disruption of production workflows, or unauthorized access to workstations used by digital artists and editors.

Technologies: [OpenEXR (PyPI)](https://junglewise.ai/threats/technologies/openexr). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-27622 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-27622 being exploited in the wild.

**How severe is CVE-2026-27622?** High severity, with a CVSS score of 7.8, published 3 March 2026.

**Which products and versions are affected?** OpenEXR (PyPI) ECOSYSTEM:introduced=2.3.0,fixed=3.2.6, ECOSYSTEM:introduced=2.3.0,fixed=3.2.6,introduced=3.3.0,fixed=3.3.8,introduced=3.4.0,fixed=3.4.6.

**Is there a fix for CVE-2026-27622?** Yes. OpenEXR (PyPI): upgrade to 3.2.6, 3.4.6 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-27622 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-27622?** Check whether you run OpenEXR (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- OpenEXR (PyPI): upgrade to 3.2.6, 3.4.6 or later

  ```sh
  pip install "OpenEXR>=3.4.6"
  ```


## Technical details

An integer overflow vulnerability exists in the 'CompositeDeepScanLine::readPixels' function of OpenEXR. When processing multipart deep EXR files, per-pixel totals are accumulated in a 32-bit unsigned integer vector ('total_sizes'). An attacker can provide a file with excessively large sample counts that cause this counter to wrap modulo 2^32. This results in an undersized buffer being allocated via 'samples[channel].resize()'. Subsequent decoding operations in 'generic_unpack_deep_pointers' use the original, large sample counts, leading to a heap-based out-of-bounds write. The vulnerability is reachable via high-level multipart deep read flows and has been patched in versions 3.2.6, 3.3.8, and 3.4.6.

## Affected products

- Academy Software Foundation OpenEXR 2.x, 3.0.x, 3.1.x, 3.2.0-3.2.5, 3.3.0-3.3.7, 3.4.0-3.4.5

## Identifiers

- CVE-2026-27622
- GHSA-cr4v-6jm6-4963
- PYSEC-2026-2846

## Timeline

- 2026-03-02: advisory: GitHub Security Advisory published by Academy Software Foundation
- 2026-03-03: disclosed: NVD publication date
- 2026-04-30: patched: Red Hat released security updates for RHEL 8.8

## References

- [https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-cr4v-6jm6-4963](https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-cr4v-6jm6-4963)
- [https://access.redhat.com/errata/RHSA-2026:12338](https://access.redhat.com/errata/RHSA-2026:12338)
- [https://access.redhat.com/errata/RHSA-2026:12339](https://access.redhat.com/errata/RHSA-2026:12339)
- [https://access.redhat.com/errata/RHSA-2026:12340](https://access.redhat.com/errata/RHSA-2026:12340)
- [https://access.redhat.com/errata/RHSA-2026:12341](https://access.redhat.com/errata/RHSA-2026:12341)
- [https://access.redhat.com/errata/RHSA-2026:16008](https://access.redhat.com/errata/RHSA-2026:16008)
- [https://access.redhat.com/errata/RHSA-2026:16009](https://access.redhat.com/errata/RHSA-2026:16009)

## Related threats

- [PYSEC-2026-2849 - OpenEXR has heap-buffer-overflow via signed integer underflow in ImfContextInit.cpp](https://junglewise.ai/threats/cve-2026-26981-openexr-has-heap-buffer-overflow-via-signed-integer-underflow-in)
- [PYSEC-2026-2844 - OpenEXR has use after free in PyObject_StealAttrString](https://junglewise.ai/threats/cve-2025-64183-openexr-has-use-after-free-in-pyobject-stealattrstring)
- [PYSEC-2026-2851 - OpenEXR has buffer overflow in PyOpenEXR_old's channels() and channel()](https://junglewise.ai/threats/cve-2025-64182-openexr-has-buffer-overflow-in-pyopenexr-old-s-channels-and)
- [PYSEC-2026-2843 - OpenEXR Makes Use of Uninitialized Memory](https://junglewise.ai/threats/cve-2025-64181-openexr-use-of-uninitialized-memory-in-generic-unpack)
- [PYSEC-2026-1748 - OpenEXR ScanLineProcess::run_fill NULL Pointer Write In "reduceMemory" Mode](https://junglewise.ai/threats/cve-2025-48073-openexr-scanlineprocess-run-fill-null-pointer-write-in)