CVE-2026-97739: Microsoft Office Excel Remote Code Execution Vulnerability
Telemetry drift only. No threshold crossed and no authority ruling changed.
CVE record, CISA KEV and EPSS as of 2026-10-18.
CVEs like this one computed, by meaning
What to do now held facts and links
- Upgrade to the fixed version for your release line, or later: 16.114.26101123; 16.0.14334.20974; 16.0.17932.21056; 16.0.10417.20228 CVE record
- Record your decision, dated and frozen with today's evidence: patch by a date · mitigated by a compensating control · deferred · accepted the risk · not affected
- Check your version against the ranges this record publishes.
What it is stated by the CNA
Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code over a network.
- weakness
- CWE-191: Integer Underflow (Wrap or Wraparound); CWE-122: Heap-based Buffer Overflow
- affected
- Microsoft 365 Apps for Enterprise; Microsoft Office 365 for Mac; Microsoft Office LTSC 2021; Microsoft Office LTSC 2024; Microsoft Office LTSC for Mac 2021; Microsoft Office LTSC for Mac 2024; Microsoft Office Online Server
- published ranges
- microsoft office online server < 16.0.10417.20228
- fixed in
- 16.114.26101123; 16.0.14334.20974; 16.0.17932.21056; 16.0.10417.20228
- severity
- 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
- assigned by
- microsoft
- published
- 2026-10-13
check us msrc.microsoft.com
Exploit code held, dated
- exploit code
- None held in the PoC-in-GitHub feed. A public repository changes this brief.
What moved held, dated
| date | EPSS | event |
|---|---|---|
| 14 Oct 2026 | 0.00798 | |
| 15 Oct 2026 | 0.00781 |
2 observations held. A step marked with a scoring model moved because the measurement was replaced, not because the vulnerability changed.
Outside the record researched, cited
This section reads the record's references and adds cited findings from outside it. It needs an account. Everything above is held facts and is complete without it.
What would change this brief held, dated
- CISA KEV
- Not listed in the catalogue we hold. A listing changes this brief.
- exploit probability
- 0.01 on 2026-10-15 (FIRST's EPSS, a probability and not evidence of exploitation). Next band line: 10% (0.10). Crossing a line changes this brief.
- fix
- Held: 16.114.26101123; 16.0.14334.20974; 16.0.17932.21056; 16.0.10417.20228. A newer fix from the CNA or OSV changes this brief.
How to check this
Every value above is held with two dates: when it was true upstream (as_of) and when we recorded it (tx_from). Re-derive the exploit probability as it stood on any date:
SELECT value, source, source_version, as_of, tx_from
FROM volatile_valid_as_of('CVE-2026-97739', '2026-10-29T23:59:59.999999Z', now());