CVE-2026-54130: Missing authentication for critical function in M365 Copilot allows an unauthorized attacker to disclose infor

This week

CRITICAL 9.8REMOTEWATCHLISTMITIGATE

CVE-2026-54130 is a critical-severity flaw (CVSS 9.8) affecting 365 copilot. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Missing authentication for critical function in M365 Copilot allows an unauthorized attacker to disclose information over a network.

Why this priority

Critical severity
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.1% (top 35%)
CISA exploited list	No
Weakness	CWE-306
Published	2026-06-18
Last modified	2026-10-26

Publisher (CNA): Microsoft Corporation · Vendor: microsoft

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-18 22:16 UTCPublished CVE record published
2026-10-26 11:10 UTCUpdated Record last modified

microsoft 365 copilot MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy 365-copilot || rpm -q 365-copilot || 365-copilot --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · flare-im · FIXED · 0.22.7-1.fc46 · FEDORA-2026-cd5e8062a1 · source

sudo dnf upgrade --advisory=FEDORA-2026-cd5e8062a1

Fedora ELN · libdnf · FIXED · 0.76.0-2.eln159 · FEDORA-2026-dbd263e9d4 · source

sudo dnf upgrade --advisory=FEDORA-2026-dbd263e9d4

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-54130?

365 copilot: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-54130 being exploited?

CVE-2026-54130 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-54130 affect?

CVE-2026-54130 affects 365 copilot. Severity is critical (CVSS 9.8). Missing authentication for critical function in M365 Copilot allows an unauthorized attacker to disclose information over a network.

How urgent is CVE-2026-54130?

Priority 64/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist

Related CVEs

CVE-2026-40363 HIGH 8.4 MITIGATE UPGRADE Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
CVE-2026-41614 MEDIUM 6.2 UPGRADE Improper access control in M365 Copilot for Desktop allows an unauthorized attacker to perform spoofing locall
CVE-2026-41100 MEDIUM 4.4 UPGRADE Improper access control in M365 Copilot allows an authorized attacker to perform spoofing locally.
CVE-2026-42831 HIGH 7.8 UPGRADE DOWNGRADE Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
CVE-2026-47645 HIGH 8.8 MITIGATE Url redirection to untrusted site ('open redirect') in Microsoft 365 Copilot's Business Chat allows an unautho

References

← Back to latest CVEs