Vulnerability in libreoffice (UBUNTU-CVE-2026-4430)

Summary

Vulnerability in libreoffice (UBUNTU-CVE-2026-4430). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 1:7.3.7-0ubuntu0.22.04.11 or later.

Original description

The description as published by the source.

Out-of-bounds write vulnerability in The Document Foundation LibreOffice via crafted OOXML documents with mismatched encryption salt parameters. This issue affects LibreOffice: from 26.2 before 26.2.3, from 25.8 before 25.8.7.

Source: OSV.dev (Open Source Vulnerabilities) OSV

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 UBUNTU-CVE-2026-4430 has been found in libreoffice.
Successful exploitation can lead to full system takeover.
What to do: upgrade libreoffice to 1:7.3.7-0ubuntu0.22.04.11 or later.
If unsure, ask your IT team or search "libreoffice UBUNTU-CVE-2026-4430" on the vendor's site.

UBUNTU-CVE-2026-4430 (libreoffice)
Attack vector: local / unauthenticated
Patched: 1:7.3.7-0ubuntu0.22.04.11 — 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 (unclassified) exists in libreoffice.

📍 Affected scope

Check the vendor advisory for the affected versions of libreoffice.

🔥 Severity

Severity: ?. Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to 1:7.3.7-0ubuntu0.22.04.11.

🛡️ 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 'libreoffice' . 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

1
Identify exposure identify
```
grep -r 'libreoffice' . | 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 libreoffice を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade libreoffice to 1:7.3.7-0ubuntu0.22.04.11
```
ステージング環境で 1:7.3.7-0ubuntu0.22.04.11 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。
3
Post-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。

Affected packages

Ubuntu:20.04:LTS libreoffice

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Ubuntu:22.04:LTS libreoffice

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:7.3.7-0ubuntu0.22.04.11"}]}]

Ubuntu:24.04:LTS libreoffice

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4:24.2.7-0ubuntu0.24.04.5"}]}]

Ubuntu:25.10 libreoffice

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4:25.8.7-0ubuntu0.25.10.1"}]}]

Ubuntu:26.04 libreoffice

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Ubuntu:26.04:LTS libreoffice

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4:26.2.3.2-0ubuntu0.26.04.1"}]}]

References

advisory ubuntu.com
advisory ubuntu.com
report ubuntu.com
report cve.org
report libreoffice.org
report git.libreoffice.org