CVE-2026-70310: Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to disclose information locally.

Routine

MEDIUM 5.5WATCHLISTMITIGATEMITIGATEMITIGATE

CVE-2026-70310 is a medium-severity flaw (CVSS 5.5) affecting 365 apps, microsoft 365, office 2019. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to disclose information locally.

Why this priority

On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.4% (top 63%)
CISA exploited list	No
Weakness	CWE-125
Published	2026-08-11
Last modified	2026-10-23

Publisher (CNA): Microsoft Corporation · Vendor: microsoft

Last updated 2026-10-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-11 17:19 UTCPublished CVE record published
2026-10-23 23:10 UTCUpdated Record last modified

microsoft 365 apps 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-apps || rpm -q 365-apps || 365-apps --version

No fixed or unaffected release known

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

microsoft microsoft 365 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 microsoft-365 || rpm -q microsoft-365 || microsoft-365 --version

No fixed or unaffected release known

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

microsoft office 2019 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 office-2019 || rpm -q office-2019 || office-2019 --version

No fixed or unaffected release known

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

microsoft office 2021 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 office-2021 || rpm -q office-2021 || office-2021 --version

No fixed or unaffected release known

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

microsoft office 2021 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 office-2021 || rpm -q office-2021 || office-2021 --version

No fixed or unaffected release known

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

microsoft office 2024 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 office-2024 || rpm -q office-2024 || office-2024 --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 · sugar-calculator · FIXED · 47-14.fc46 · FEDORA-2026-38eeb9e279 · source

sudo dnf upgrade --advisory=FEDORA-2026-38eeb9e279

Fedora ELN · selinux-policy · FIXED · 45.23-1.eln159 · FEDORA-2026-3668c969a2 · source

sudo dnf upgrade --advisory=FEDORA-2026-3668c969a2

Microsoft Word 2016 (32-bit edition) · KB5002901 · FIXED · 16.0.5565.1000 · KB5002901 · source

Install KB5002901 via Windows Update, then verify: Get-HotFix -Id KB5002901

Microsoft Word 2016 (64-bit edition) · KB5002901 · FIXED · 16.0.5565.1000 · KB5002901 · source

Install KB5002901 via Windows Update, then verify: Get-HotFix -Id KB5002901

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-2026-70310?

365 apps: mitigate or apply the listed mitigation; microsoft 365: mitigate or apply the listed mitigation; office 2019: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-70310 being exploited?

CVE-2026-70310 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-2026-70310 affect?

CVE-2026-70310 affects 365 apps, microsoft 365, office 2019. Severity is medium (CVSS 5.5). Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to disclose information locally.

How urgent is CVE-2026-70310?

Priority 33/100. On your watchlist

Software pages

Microsoft Office vulnerabilities

Related CVEs

CVE-2026-68813 MEDIUM 5.5 MITIGATE MITIGATE Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.

References

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