CVE-2026-55018: Use after free in Microsoft Office allows an unauthorized attacker to execute code locally.

highCVSS 7.8CVE-2026-55018

Use after free in Microsoft Office allows an unauthorized attacker to execute code locally.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: high — CVSS 7.8
Published: 2026-07-14
Last updated: 2026-07-16
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-55018

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-550180.34% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 27% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-55018	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

unknownexploitedNCSC-2026-0237 [1.02] [H/H] Vulnerabilities Fixed in Microsoft Officencsc-nl
unknownexploitedNCSC-2026-0237 [1.01] [H/H] Vulnerabilities fixed in Microsoft Officencsc-nl
unknownMultiple vulnerabilities in Microsoft Office (July 15, 2026)cert-fr-avis
unknownexploitedNCSC-2026-0237 [1.00] [M/H] Vulnerabilities fixed in Microsoft Officencsc-nl
highCVE-2026-55018: Microsoft Office Remote Code Execution Vulnerabilitymsrc

Recent advisories for Use after free

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

highCVE-2026-67300: FreeRDP before 3.29.0 contains client-side heap use-after-free vulnerabilities in the async up…nvd · 2026-08-01
highCVE-2026-67299: FreeRDP before 3.29.0 contains a client-side heap use-after-free in the async update message p…nvd · 2026-08-01
highCVE-2026-65981: Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.15.0, a server…nvd · 2026-07-31
highCVE-2026-63035: A heap use-after-free vulnerability in the TransferSubscriptions service in open62541 may allo…nvd · 2026-07-30
unknownCVE-2026-13117: An incomplete guard in OpenVPN 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote…nvd · 2026-07-30
unknownCVE-2026-12996: A use-after-free in OpenVPN 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote au…nvd · 2026-07-30