What is GHSA-78c8-h6hm-94hg?

GHSA-78c8-h6hm-94hg is a security advisory published by GitHub Security Advisories with High severity. Deserialization of untrusted data in Microsoft Exchange Server allows an authorized attacker to...

Which CVE IDs does GHSA-78c8-h6hm-94hg cover?

GHSA-78c8-h6hm-94hg covers the following CVE IDs: CVE-2026-55009. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of GHSA-78c8-h6hm-94hg?

GHSA-78c8-h6hm-94hg has a CVSS v3 base score of 7.8, published by GitHub Security Advisories.

GHSA-78c8-h6hm-94hgHighCVSS 7.8

Deserialization of untrusted data in Microsoft Exchange Server allows an authorized attacker to...

Vendor

GitHub Security Advisories

Published

July 14, 2026

Last Modified

July 14, 2026

🔗 CVE IDs covered (1)

CVE-2026-55009 →

📋 Description

Deserialization of untrusted data in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.

🔗 References (3)

https://nvd.nist.gov/vuln/detail/CVE-2026-55009
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55009
https://github.com/advisories/GHSA-78c8-h6hm-94hg