- Critical 9.8
- Known exploited (CISA KEV)
CVE-2026-58644
Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
Scores
The facts
- Published
- 14 July 2026
- Last changed
- 17 July 2026
- NVD status
- Analyzed
- Severity
- Critical, CVSS 9.8 out of 10 (version 3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- Affects
- microsoft sharepoint server
- Known exploited
- Yes. CISA added it to the Known Exploited Vulnerabilities catalogue on 16 July 2026.
- EPSS
- 15.9% chance of exploitation activity in the next 30 days (percentile 97).
Is there a Securelyn advisory?
Not yet. Securelyn writes plain-English advisories for the flaws that matter most to businesses. Subscribe to the digest to hear about them.