Vulnerability in Openexr (CVE-2026-34379)
Summary
Vulnerability in Openexr (CVE-2026-34379). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 3.2.7 or later.
Original description
The description as published by the source.
OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From 3.2.0 to before 3.2.7, 3.3.9, and 3.4.9, a misaligned memory write vulnerability exists in LossyDctDecoder_execute() in src/lib/OpenEXRCore/internal_dwa_decoder.h:749. When decoding a DWA or DWAB-compressed EXR file containing a FLOAT-type channel, the decoder performs an in-place HALF→FLOAT conversion by casting an unaligned uint8_t * row pointer to float * and writing through it. Because the row buffer may not be 4-byte aligned, this constitutes undefined behavior under the C standard and crashes immediately on architectures that enforce alignment (ARM, RISC-V, etc.). On x86 it is silently tolerated at runtime but remains exploitable via compiler optimizations that assume aligned access. This vulnerability is fixed in 3.2.7, 3.3.9, and 3.4.9.
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-2026-34379 has been found in Openexr.
Risk of unauthorized operations or information disclosure. CVSS score: 7.1/10.
What to do: upgrade Openexr to 3.2.7 or later.
If unsure, ask your IT team or search "Openexr CVE-2026-34379" on the vendor's site.
CVE-2026-34379 (Openexr) — CWE-704 / CVSS v3 7.1
Attack vector: remote (network-reachable) / unauthenticated
Patched: 3.2.7 — apply immediately
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.
A vulnerability (CWE-704) exists in Openexr.
Check the vendor advisory for the affected versions of Openexr.
Severity: High (CVSS 7.1/10). Risk of unauthorized operations or information disclosure.
Update to 3.2.7.
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
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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。 -
2Apply patch patch
Upgrade Openexr to 3.2.7ステージング環境で 3.2.7 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-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
- Debian DEBIAN-CVE-2026-34379 openexr
- Ubuntu UBUNTU-CVE-2026-34379 openexr