CVE-2026-50657: Exposure of private personal information to an unauthorized actor in Microsoft Defender allows an authorized a

Routine

MEDIUM 4.7WATCHLISTUPGRADE

CVE-2026-50657 is a medium-severity flaw (CVSS 4.7) affecting defender for endpoint. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Exposure of private personal information to an unauthorized actor in Microsoft Defender allows an authorized attacker to disclose information locally.

Why this priority

On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	4.7 (Medium)
Attack vector	Local
Attack complexity	High
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 67%)
CISA exploited list	No
Weakness	CWE-359
Published	2026-07-14
Last modified	2026-10-24

Publisher (CNA): Microsoft Corporation · Vendor: microsoft

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-14 18:17 UTCPublished CVE record published
2026-10-24 21:10 UTCUpdated Record last modified

microsoft defender for endpoint UPGRADE

Affected: >= 101.0.0 and < 101.26042.0020

Fixed in: 101.26042.0020

Safe to downgrade to: a release before 101.0.0

1. Check installed version

apt-cache policy defender-for-endpoint || rpm -q defender-for-endpoint || defender-for-endpoint --version

2. UPGRADE to 101.26042.0020 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade defender-for-endpoint

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade defender-for-endpoint

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 101.0.0 (Debian / Ubuntu)

apt-cache madison defender-for-endpoint sudo apt install defender-for-endpoint=<VERSION_BEFORE_101.0.0> sudo apt-mark hold defender-for-endpoint

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list defender-for-endpoint sudo dnf downgrade defender-for-endpoint-<VERSION_BEFORE_101.0.0> sudo dnf versionlock add defender-for-endpoint

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2026-50657?

defender for endpoint: upgrade to 101.26042.0020. Exact commands for each OS are on this page.

Is CVE-2026-50657 being exploited?

CVE-2026-50657 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-2026-50657 affect?

CVE-2026-50657 affects defender for endpoint. Severity is medium (CVSS 4.7). Exposure of private personal information to an unauthorized actor in Microsoft Defender allows an authorized attacker to disclose information locally.

How urgent is CVE-2026-50657?

Priority 30/100. On your watchlist

Software pages

Windows Defender vulnerabilities

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CVE-2026-54123 MEDIUM 5.5 UPGRADE Exposure of sensitive information to an unauthorized actor in Microsoft Defender for Endpoint allows an author

References

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