CVE-2026-55133Disclosure(microsoft / 365_apps)

LOWCVSS 7.8 · HIGH

Signal is active with 1 mentions in latest observed window

Immediate actions

Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

NVD description

Heap-based buffer overflow in Microsoft Office OneNote allows an unauthorized attacker to execute code locally.

microsoft CVEs Back to dashboard

0.5/ 10 priority

Sources & remediation

Vendor / third-party advisories

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55133

Weakness type (CWE)

CWE-122

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

NONE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

365_apps
microsoft_365
office_2021
office_2024

Threat summary

1 mentions across 1 observed day

What's happening

Technical details provided in 1 signal
Disclosure: 1 classified signal
1 total mentions across 1 day

Affected systems

Vendors

microsoft

Products

365_appsmicrosoft_365office_2021office_2024

1 version affected across 4 products

Deep dive

Activity timeline1 mentions / 1d

Signal classification1 categories

Disclosure

1100.0%

Referenced assets1 URL

By indicator

https://windowsforum.com/threads/cve-2026-55133-onenote-rce-why-microsoft-rates-it-av-l.438748/?utm_source=x&utm_medium=social&utm_campaign=news_node84

Full discourse1 post

Windows Forum@windowsforum97d
Disclosure
🪟 OneNote’s “remote” code execution is technically local because the malicious file must reach the victim first. CVSS loves a loophole: remote danger, local trigger. https://windowsforum.com/threads/cve-2026-55133-onenote-rce-why-microsoft-rates-it-av-l.438748/?utm_source=x&utm_medium=social&utm_campaign=news_node84 #RemoteCodeExecution #CvssAttackVector #Cve202655133 #MicrosoftOnenote https://t.co/B604rFrJ4h
Post summary
The tweet discusses CVE‑2026‑55133, explaining that OneNote’s remote‑code‑execution is actually triggered by a locally delivered malicious file and notes its CVSS classification.
0000016
1.2K followersView on X

CPE platform detail5 entries

Part:

Vendor:

Product:

Version:

Target SW:

Target HW:

5 of 5 entries

Part	Vendor	Product	Version	Target SW	Target HW
App	microsoft	365_apps	-	-	x64
App	microsoft	365_apps	-	-	x86
App	microsoft	microsoft_365	-	macos	-
App	microsoft	office_2021	-	macos	-
App	microsoft	office_2024	-	macos	-

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