Vulnerability in libreoffice (UBUNTU-CVE-2026-8356)

Summary

Vulnerability in libreoffice (UBUNTU-CVE-2026-8356). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 1:7.3.7-0ubuntu0.22.04.12 or later.

Original description

The description as published by the source.

LibreOffice can import presentations in the legacy binary PPT format. A stack buffer overflow existed when importing a colour-replacement record. Two fixed-size colour tables were filled from the file, but the write position was not reset between the two passes over the record, so a file whose combined colour counts exceeded the table size wrote past the end of the tables on the stack. In fixed versions the unused second pass is no longer read into those tables.

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-2026-8356 has been found in libreoffice.
Risk of unauthorized operations or information disclosure.
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-2026-8356" on the vendor's site.

UBUNTU-CVE-2026-8356 (libreoffice)
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: ?. Risk of unauthorized operations or information disclosure.

🔧 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