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CVE-2026-26981
Vulnerability in openexr (CVE-2026-26981)
Summary
vulnerability in openexr (CVE-2026-26981). Risk of unauthorized operations or information disclosure. Exploitable via ``istream_nonparallel_read``. Mitigation: upgrade to `3.4.5` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-26981** has been found in openexr.
Attackers can target a specific entry point like ``istream_nonparallel_read`` over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: ?/10.
What to do: upgrade openexr to **3.4.5** or later.
If unsure, ask your IT team or search "openexr CVE-2026-26981" on the vendor's site.
CVE-2026-26981 (openexr) — CWE-195 /
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: `istream_nonparallel_read` / `ImfContextInit.cpp` / `IStream` / `size_t`
Patched: `3.4.5` — 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.
❓ What is the problem
**A vulnerability** (CWE-195) exists in openexr. Attackers reach the vulnerable code path via ``istream_nonparallel_read`` without authentication.
📍 Affected scope
openexr — . Attack surface: `istream_nonparallel_read` / `ImfContextInit.cpp` / `IStream` / `size_t`.
🔥 Severity
Severity: ?. Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **3.4.5**.
🛡️ Workaround
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
🔍 Detection
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 (7 steps)
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。
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6Apply patch patch
Upgrade openexr to 3.4.5ステージング環境で 3.4.5 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と、Step 3 で見つけた異常検知の続報チェックを含めること。
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7Post-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 Step 3 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
PyPI
openexr
[{"type":"ECOSYSTEM","events":[{"introduced":"3.4.0"},{"fixed":"3.4.5"}]}]
References
- advisory https://nvd.nist.gov/vuln/detail/CVE-2026-26981
- advisory https://github.com/advisories/GHSA-q6vj-wxvf-5m8c
- package https://github.com/AcademySoftwareFoundation/openexr
- package https://pypi.org/project/openexr
- web https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-q6vj-wxvf-5m8c
- web https://github.com/AcademySoftwareFoundation/openexr/commit/6bb2ddf1068573d073edf81270a015b38cc05cef
- web https://github.com/AcademySoftwareFoundation/openexr/commit/d2be382758adc3e9ab83a3de35138ec28d93ebd8