Out-of-Bounds Write in OpenEXR (CVE-2026-55059)
Summary
Out-of-bounds write in OpenEXR (CVE-2026-55059). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
OpenEXR is the reference implementation and specification for the EXR image format, widely used in the motion picture industry. Versions prior to 3.2.10, 3.3.12 and 3.4.13 contain a heap out-of-bounds write in Imf_4_0::SampleCountChannel::set(int r, unsigned int newNumSamples[]). The row-based sample-count setter computes the target Y coordinate with dataWindow.min.x instead of dataWindow.min.y. For a valid deep image data window where min.x != min.y, a valid row index can be translated into an invalid Y coordinate, causing writes before the allocated _numSamples buffer. The vulnerability is reachable through the public OpenEXRUtil DeepImage API and can lead to heap corruption and process crashes. This issue has been fixed in versions 3.2.10, 3.3.12 and 3.4.13.
Source: NIST National Vulnerability Database NVD
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-55059 has been found in OpenEXR.
Risk of unauthorized operations or information disclosure. CVSS score: 6.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "OpenEXR CVE-2026-55059" on the vendor's site.
CVE-2026-55059 (OpenEXR) — CWE-787 / CVSS v3 6.1
Attack vector: local / unauthenticated
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Out-of-bounds write (CWE-787) exists in OpenEXR.
Check the vendor advisory for the affected versions of OpenEXR.
Severity: Medium (CVSS 6.1/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'OpenEXR' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'OpenEXR' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
OpenEXRを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2026-55059 openexr Fixed in: 3.4.13-r0
- Debian DEBIAN-CVE-2026-55059 openexr
- Ubuntu UBUNTU-CVE-2026-55059 openexr
References
- web github.com