CVE-2026-70338: Improper control of generation of code ('code injection') in Microsoft PowerShell allows an unauthorized attac

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HIGH 7.8WATCHLISTUPGRADE

CVE-2026-70338 is a high-severity flaw (CVSS 7.8) affecting powershell. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Improper control of generation of code ('code injection') in Microsoft PowerShell allows an unauthorized attacker to bypass a security feature locally.

Why this priority

High severity
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.4% (top 71%)
CISA exploited list	No
Weakness	CWE-94
Published	2026-08-11
Last modified	2026-08-14

Publisher (CNA): Microsoft Corporation · Vendor: microsoft

Last updated 2026-08-14 · 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
2026-08-14 17:09 UTCUpdated Record last modified

microsoft powershell UPGRADE

Affected: >= 7.4 and < 7.4.19.0 · >= 7.5 and < 7.5.10.0 · >= 7.6 and < 7.6.5

Fixed in: 7.4.19.0, 7.5.10.0, 7.6.5

Safe to downgrade to: a release before 7.4

1. Check installed version

apt-cache policy powershell || rpm -q powershell || powershell --version

2. UPGRADE to 7.4.19.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade powershell

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade powershell

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 7.4 (Debian / Ubuntu)

apt-cache madison powershell sudo apt install powershell=<VERSION_BEFORE_7.4> sudo apt-mark hold powershell

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

dnf --showduplicates list powershell sudo dnf downgrade powershell-<VERSION_BEFORE_7.4> sudo dnf versionlock add powershell

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.

Advisories and coverage

Official advisories

Microsoft MSRC Update Guide: CVE-2026-70338 Microsoft PowerShell Security Feature Bypass Vulnerability 2026-10-26

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-2026-70338?

powershell: upgrade to 7.4.19.0, 7.5.10.0, 7.6.5. Exact commands for each OS are on this page.

Is CVE-2026-70338 being exploited?

CVE-2026-70338 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-2026-70338 affect?

CVE-2026-70338 affects powershell. Severity is high (CVSS 7.8). Improper control of generation of code ('code injection') in Microsoft PowerShell allows an unauthorized attacker to bypass a security feature locally.

How urgent is CVE-2026-70338?

Priority 40/100. High severity; On your watchlist

Software pages

PowerShell vulnerabilities

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References

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