Outlook vulnerabilities: known CVEs & security history
Microsoft · Actively exploited · 12 tracked CVEs · 1 actively exploited · updated November 2026 · what is a CVE? →
This is the full list of known vulnerabilities (CVEs) across all Outlook release lines — 12 in total, with 1 actively exploited in the wild. A CVE here doesn't mean your version is affected — check Outlook's current status and the safe version to run.
Known Outlook CVEs
Actively-exploited and most-severe first. Open any CVE for full details.
| CVE | Severity | CVSS | EPSS | Year |
|---|---|---|---|---|
| CVE-2023-35311⚡ exploited | high | 8.8 | 16% | 2023 |
| CVE-2026-78519 | high | 8.8 | 1% | 2026 |
| CVE-2026-69629 | high | 8.8 | 1% | 2026 |
| CVE-2026-70329 | high | 8.8 | 1% | 2026 |
| CVE-2024-30103 | high | 8.8 | 3% | 2024 |
| CVE-2024-21378 | high | 8.8 | 11% | 2024 |
| CVE-2018-0851 | high | 8.8 | 19% | 2018 |
| CVE-2026-42893 | high | 7.4 | 0% | 2026 |
| CVE-2026-80073 | medium | 6.5 | 1% | 2026 |
| CVE-2024-43482 | medium | 6.5 | 1% | 2024 |
| CVE-2023-36893 | medium | 6.5 | 2% | 2023 |
| CVE-2026-62882 | medium | 4.3 | 1% | 2026 |
Is my Outlook version affected?
The list above spans every release. To know whether your version is affected — and the minimum safe version to upgrade to — check it directly.
Check your Outlook version → · Monitor Outlook for new CVEs →
Outlook vulnerabilities — frequently asked
How many known vulnerabilities does Outlook have?
IsItPatched tracks 12 CVEs for Outlook, 1 of which is actively exploited (CISA KEV). 0 are critical-severity and 8 high-severity. These span every release line — what matters is whether the version you run is affected.
Does Outlook have any actively-exploited vulnerabilities?
Yes — 1 Outlook CVE is in CISA's Known Exploited Vulnerabilities catalog, meaning it is confirmed exploited in the wild. Patch it as a priority.
What is the most severe Outlook vulnerability?
Among tracked issues, CVE-2023-35311 (HIGH, CVSS 8.8), which is actively exploited, ranks highest — a CWE-367 weakness.
Is Outlook safe to use?
It depends on the version. The latest supported Outlook release clears the known issues; older versions may still be affected. Check the exact version you run for a verdict.
CVE data aggregated from NVD, CISA KEV and EPSS (FIRST.org). Related: Outlook security status · Outlook end-of-life · actively-exploited CVEs. Always verify against Microsoft's advisories — see our disclaimer.