CVE-2026-77484: Deserialization of untrusted data in SQL Server allows an authorized attacker to execute code over a network.

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HIGH 8.8WATCHLISTUPGRADEUPGRADEUPGRADE

CVE-2026-77484 is a high-severity flaw (CVSS 8.8) affecting sql server 2019, sql server 2022, sql server 2025. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Deserialization of untrusted data in SQL Server allows an authorized attacker to execute code over a network.

Why this priority

High severity
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.7% (top 23%)
CISA exploited list	No
Weakness	CWE-502
Published	2026-09-08
Last modified	2026-09-15

Publisher (CNA): Microsoft Corporation · Vendor: microsoft

Last updated 2026-09-15 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-08 18:20 UTCPublished CVE record published
2026-09-15 16:08 UTCUpdated Record last modified

microsoft sql server 2019 UPGRADE

Affected: < 15.0.2190.7 · >= 15.0.4003.23 and < 15.0.4490.9

Fixed in: 15.0.2190.7, 15.0.4490.9

Safe to downgrade to: a release before 15.0.4003.23

1. Check installed version

apt-cache policy sql-server-2019 || rpm -q sql-server-2019 || sql-server-2019 --version

2. UPGRADE to 15.0.2190.7 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade sql-server-2019

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade sql-server-2019

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 15.0.4003.23 (Debian / Ubuntu)

apt-cache madison sql-server-2019 sudo apt install sql-server-2019=<VERSION_BEFORE_15.0.4003.23> sudo apt-mark hold sql-server-2019

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

dnf --showduplicates list sql-server-2019 sudo dnf downgrade sql-server-2019-<VERSION_BEFORE_15.0.4003.23> sudo dnf versionlock add sql-server-2019

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.

microsoft sql server 2022 UPGRADE

Affected: < 16.0.1200.5 · >= 16.0.4003.1 and < 16.0.4275.2

Fixed in: 16.0.1200.5, 16.0.4275.2

Safe to downgrade to: a release before 16.0.4003.1

1. Check installed version

apt-cache policy sql-server-2022 || rpm -q sql-server-2022 || sql-server-2022 --version

2. UPGRADE to 16.0.1200.5 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade sql-server-2022

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade sql-server-2022

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 16.0.4003.1 (Debian / Ubuntu)

apt-cache madison sql-server-2022 sudo apt install sql-server-2022=<VERSION_BEFORE_16.0.4003.1> sudo apt-mark hold sql-server-2022

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

dnf --showduplicates list sql-server-2022 sudo dnf downgrade sql-server-2022-<VERSION_BEFORE_16.0.4003.1> sudo dnf versionlock add sql-server-2022

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.

microsoft sql server 2025 UPGRADE

Affected: < 17.0.1135.8 · >= 17.0.4006.2 and < 17.0.4085.5

Fixed in: 17.0.1135.8, 17.0.4085.5

Safe to downgrade to: a release before 17.0.4006.2

1. Check installed version

apt-cache policy sql-server-2025 || rpm -q sql-server-2025 || sql-server-2025 --version

2. UPGRADE to 17.0.1135.8 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade sql-server-2025

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade sql-server-2025

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 17.0.4006.2 (Debian / Ubuntu)

apt-cache madison sql-server-2025 sudo apt install sql-server-2025=<VERSION_BEFORE_17.0.4006.2> sudo apt-mark hold sql-server-2025

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

dnf --showduplicates list sql-server-2025 sudo dnf downgrade sql-server-2025-<VERSION_BEFORE_17.0.4006.2> sudo dnf versionlock add sql-server-2025

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.

Exact fixes by distribution

Fedora 46 · python3.11 · FIXED · 3.11.18-1.fc46 · FEDORA-2026-cc775894f4 · source

sudo dnf upgrade --advisory=FEDORA-2026-cc775894f4

Microsoft SQL Server 2019 for x64-based Systems (GDR) · KB5122773 · FIXED · 15.0.2190.7 · KB5122773 · source

Install KB5122773 via Windows Update, then verify: Get-HotFix -Id KB5122773

Microsoft SQL Server 2022 for x64-based Systems (GDR) · KB5122771 · FIXED · 16.0.1200.5 · KB5122771 · source

Install KB5122771 via Windows Update, then verify: Get-HotFix -Id KB5122771

Microsoft SQL Server 2025 for x64-based Systems (GDR) · KB5122770 · FIXED · 17.0.1135.8 · KB5122770 · source

Install KB5122770 via Windows Update, then verify: Get-HotFix -Id KB5122770

Microsoft SQL Server 2019 for x64-based Systems (CU 32) · KB5122772 · FIXED · 15.0.4490.9 · KB5122772 · source

Install KB5122772 via Windows Update, then verify: Get-HotFix -Id KB5122772

Microsoft SQL Server 2025 for x64-based Systems (CU8) · KB5122769 · FIXED · 17.0.4085.5 · KB5122769 · source

Install KB5122769 via Windows Update, then verify: Get-HotFix -Id KB5122769

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-2026-77484?

sql server 2019: upgrade to 15.0.2190.7, 15.0.4490.9; sql server 2022: upgrade to 16.0.1200.5, 16.0.4275.2; sql server 2025: upgrade to 17.0.1135.8, 17.0.4085.5. Exact commands for each OS are on this page.

Is CVE-2026-77484 being exploited?

CVE-2026-77484 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-2026-77484 affect?

CVE-2026-77484 affects sql server 2019, sql server 2022, sql server 2025. Severity is high (CVSS 8.8). Deserialization of untrusted data in SQL Server allows an authorized attacker to execute code over a network.

How urgent is CVE-2026-77484?

Priority 55/100. High severity; On your watchlist

Software pages

Microsoft SQL Server vulnerabilities

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References

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