CVE-2026-108457: Out-of-bounds write in Microsoft Windows PDF allows an unauthorized attacker to execute code over a network.

Q: How do I fix CVE-2026-108457?

windows 10 21h2: upgrade to 10.0.19044.7807; windows 10 22h2: upgrade to 10.0.19045.7807; windows 11 23h2: upgrade to 10.0.22631.7652. Exact commands for each OS are on this page.

Q: Is CVE-2026-108457 being exploited?

CVE-2026-108457 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-108457 affect?

CVE-2026-108457 affects windows 10 21h2, windows 10 22h2, windows 11 23h2. Severity is high (CVSS 8.1). Out-of-bounds write in Microsoft Windows PDF allows an unauthorized attacker to execute code over a network.

Q: How urgent is CVE-2026-108457?

Priority 52/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

This month

HIGH 8.1REMOTEWATCHLISTUPGRADEUPGRADEUPGRADE

CVE-2026-108457 is a high-severity flaw (CVSS 8.1) affecting windows 10 21h2, windows 10 22h2, windows 11 23h2. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Out-of-bounds write in Microsoft Windows PDF allows an unauthorized attacker to execute code over a network.

Why this priority

High severity
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.8% (top 44%)
CISA exploited list	No
Weakness	CWE-787
Published	2026-10-13
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

2026-10-13 19:18 UTCPublished CVE record published
2026-10-26 20:15 UTCUpdated Record last modified

microsoft windows 10 21h2 UPGRADE

Affected: < 10.0.19044.7807

Fixed in: 10.0.19044.7807

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

microsoft windows 10 22h2 UPGRADE

Affected: < 10.0.19045.7807

Fixed in: 10.0.19045.7807

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

microsoft windows 11 23h2 UPGRADE

Affected: < 10.0.22631.7652

Fixed in: 10.0.22631.7652

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

microsoft windows server 2022 UPGRADE

Affected: < 10.0.20348.5761

Fixed in: 10.0.20348.5761

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

microsoft windows server 2025 UPGRADE

Affected: < 10.0.26100.33650

Fixed in: 10.0.26100.33650

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

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-2026-108457?

windows 10 21h2: upgrade to 10.0.19044.7807; windows 10 22h2: upgrade to 10.0.19045.7807; windows 11 23h2: upgrade to 10.0.22631.7652. Exact commands for each OS are on this page.

Is CVE-2026-108457 being exploited?

CVE-2026-108457 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-2026-108457 affect?

CVE-2026-108457 affects windows 10 21h2, windows 10 22h2, windows 11 23h2. Severity is high (CVSS 8.1). Out-of-bounds write in Microsoft Windows PDF allows an unauthorized attacker to execute code over a network.

How urgent is CVE-2026-108457?

Priority 52/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Windows vulnerabilities · Windows Server vulnerabilities

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References

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