5.5

CVE-2026-55138: microsoft 365_apps Untrusted Pointer Dereference

CVSS: 5.5v3.1MediumAnalyzed
Published 14-07-2026Last modified 08-10-2026
Open JSON

Vulnerability summary

CVE-2026-55138 is a medium (CVSS 5.5) Untrusted Pointer Dereference vulnerability in microsoft 365_apps. EPSS estimates a 0.54% chance of exploitation in the next 30 days, higher than 44.6% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.54%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 14-07-2026
    PublishedVulnerability first disclosed.
  2. 08-10-2026
    Last modifiedVulnerability information updated.

Description

Untrusted pointer dereference in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.54%

Chance of exploitation in the next 30 days

Percentile

45%

Versus all other CVEs

30-day change

0.00 pp

From 0.54% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.54%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Microsoft15 products

1 vendor · 15 products

References

1 links