Vulnerability in libreoffice (UBUNTU-CVE-2026-8357)

Summary

Vulnerability in libreoffice (UBUNTU-CVE-2026-8357). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 1:7.3.7-0ubuntu0.22.04.12 or later.

Original description

The description as published by the source.

LibreOffice Calc compiles cell formulas when opening a spreadsheet. A heap buffer overflow existed when compiling a very long formula made up of many opening tokens. The array that tracks nesting depth was allocated one element too small for that worst case, so such a formula wrote one element past its end. In fixed versions the array is sized to hold the largest possible nesting.

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-2026-8357 has been found in libreoffice.
Successful exploitation can lead to full system takeover.
What to do: upgrade libreoffice to 1:7.3.7-0ubuntu0.22.04.12 or later.
If unsure, ask your IT team or search "libreoffice UBUNTU-CVE-2026-8357" on the vendor's site.

UBUNTU-CVE-2026-8357 (libreoffice)
Attack vector: local / unauthenticated
Patched: 1:7.3.7-0ubuntu0.22.04.12 — 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 1:7.3.7-0ubuntu0.22.04.12.

🛡️ 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 1:7.3.7-0ubuntu0.22.04.12
```
ステージング環境で 1:7.3.7-0ubuntu0.22.04.12 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":"1:7.3.7-0ubuntu0.22.04.12"}]}]

Ubuntu:24.04:LTS libreoffice

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4:24.2.7-0ubuntu0.24.04.6"}]}]

Ubuntu:25.10 libreoffice

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

Ubuntu:26.04:LTS libreoffice

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4:26.2.4.2-0ubuntu0.26.04.2"}]}]

References

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