Microsoft Office Outlook Remote Code Execution Vulnerability
- Exploited
- No known exploitation
- Fix
- Fixed in 16.0.14334.21048, 16.0.17932.21140
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 16.0.14334.21048, 16.0.17932.21140.
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 17/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: total
Summary
Microsoft Office Outlook is affected by a flaw that lets an attacker run code on a victim's system over the network without logging in, though the victim must take an action such as opening a crafted message. The bug is a heap-based buffer overflow, and an attacker who exploits it could execute arbitrary code.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
Heap-based buffer overflow in Microsoft Office Outlook allows an unauthorized attacker to execute code over a network.
cve.now Index
- Exploitation0/40No signal
- Exposure7/25Reachable over the network without a login · Unknown: No advisory context yet
- Reach?/20Unknown. No tracked technology or package matched
- Severity9.8/10CVSS 8.8, total technical impact per CISA
- No patch0/5No signal
What would change the score
- Would score about 72 if added to CISA KEV
- Would score about 67 if CISA's SSVC rates exploitation active
- Would score about 32 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 16.0.14334.21048, 16.0.17932.21140.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-110043 (Microsoft Office Outlook Remote Code Execution Vulnerability), using the cve.now data below. Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only. What cve.now has for CVE-2026-110043 (entry last updated 2026-11-10): Affected: - Microsoft Microsoft 365 Apps for Enterprise: from 16.0.1 - Microsoft Microsoft Office LTSC 2021: from 16.0.1, fixed in 16.0.14334.21048 - Microsoft Microsoft Office LTSC 2024: from 16.0.0, fixed in 16.0.17932.21140 Fixed versions: 16.0.14334.21048, 16.0.17932.21140. Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory. CISA KEV: CVE-2026-110043 is not listed as of cve.now's last read. This KEV status is for CVE-2026-110043 only. If you also check another CVE, look up its own KEV status; never assume it from this one. How to check: - Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory. Verify against the linked advisories before concluding, and cite the date you read each one: - https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-110043 Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing. Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action. Entry: https://cve.now/CVE-2026-110043 For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-110043.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- First seen by cve.now
- Record last updated
Affected versions
- Microsoft Microsoft 365 Apps for Enterprise
From 16.0.1
- Microsoft Microsoft Office LTSC 2021
From 16.0.1 · fixed in 16.0.14334.21048
- Microsoft Microsoft Office LTSC 2024
From 16.0.0 · fixed in 16.0.17932.21140
Evidence 3
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Patch
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-110043
Is CVE-2026-110043 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-110043?
Microsoft 365 Apps for Enterprise: from 16.0.1. Microsoft Office LTSC 2021: from 16.0.1 before 16.0.14334.21048. Microsoft Office LTSC 2024: from 16.0.0 before 16.0.17932.21140.Source: cve.now feed data
How do I fix CVE-2026-110043?
Upgrade to a fixed version: 16.0.14334.21048, 16.0.17932.21140.Source: cve.now feed data