What is CVE-2026-81949?
Integer overflow or wraparound in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
The record classifies CVE-2026-81949 under weakness class CWE-190. Its CVSS v3 base vector states that the flaw requires local access to the host, needs no prior authentication, needs a user to take an action first, and has high impact on confidentiality, integrity, availability. 9 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 44 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 7.8 — HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - EPSS (FIRST)
- 0.4% probability of exploitation in the next 30 days, higher than 38.4% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 5.4/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-09-08, last modified 2026-10-08
Is CVE-2026-81949 being exploited?
It currently carries a trending score of 42 in the Threadlinqs vulnerability feed.
Affected products and versions
- Microsoft: 365 Apps for Enterprise, Excel 2016, Office 2016, Office 2019, Office 365 for Mac, Office LTSC 2021, Office LTSC 2024, Office LTSC for Mac 2021, Office LTSC for Mac 2024
How to fix CVE-2026-81949
No vendor patch reference has been recorded for CVE-2026-81949 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-81949
2 tracked threats in the Threadlinqs corpus reference CVE-2026-81949, either in the campaign’s CVE list or as an indicator on the campaign record.
- September 2026 Microsoft Patch Tuesday — Record 966+ Vulnerabilities with Two Actively Exploited Zero-Days (CVE-2026-81963, CVE-2026-85880) and Multiple Critical Wormable RCEs — CRITICAL · 2026-09-08
- Microsoft September 2026 Patch Tuesday — 999 CVEs, 3 actively exploited zero-days (CVE-2026-85880, CVE-2026-81963, CVE-2026-85046) — CRITICAL · 2026-09-08
Sources
Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on .