CVE-2025-22166: This High severity DoS (Denial of Service) vulnerability was introduced in version 2.0 of Confluence Data Cent

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HIGH 7.5REMOTEUPGRADEUPGRADE

CVE-2025-22166 is a high-severity flaw (CVSS 7.5) affecting confluence data center, confluence server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

This High severity DoS (Denial of Service) vulnerability was introduced in version 2.0 of Confluence Data Center. This DoS (Denial of Service) vulnerability, with a CVSS Score of 8.3, allows an attacker to cause a resource to be unavailable for its intended users by temporarily or indefinitely disrupting services of a host connected to a network. Atlassian recommends that Confluence Data Center customers upgrade to latest version, if you ar

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 57%)
CISA exploited list	No
Weakness	CWE-405
Published	2025-10-21
Last modified	2026-10-08

Publisher (CNA): Atlassian · Vendor: atlassian

Last updated 2026-10-08 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-10-21 16:15 UTCPublished CVE record published
2026-10-08 11:10 UTCUpdated Record last modified

atlassian confluence data center UPGRADE

Affected: >= 8.5.0 and < 8.5.25 · >= 9.2.0 and < 9.2.7 · >= 10.0.0 and < 10.0.2

Fixed in: 8.5.25, 9.2.7, 10.0.2

Safe to downgrade to: a release before 8.5.0

1. Check installed version

apt-cache policy confluence-data-center || rpm -q confluence-data-center || confluence-data-center --version

2. UPGRADE to 8.5.25 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade confluence-data-center

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade confluence-data-center

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 8.5.0 (Debian / Ubuntu)

apt-cache madison confluence-data-center sudo apt install confluence-data-center=<VERSION_BEFORE_8.5.0> sudo apt-mark hold confluence-data-center

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

dnf --showduplicates list confluence-data-center sudo dnf downgrade confluence-data-center-<VERSION_BEFORE_8.5.0> sudo dnf versionlock add confluence-data-center

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.

atlassian confluence server UPGRADE

Affected: >= 8.5.0 and < 8.5.25 · >= 9.2.0 and < 9.2.7 · >= 10.0.0 and < 10.0.2

Fixed in: 8.5.25, 9.2.7, 10.0.2

Safe to downgrade to: a release before 8.5.0

1. Check installed version

apt-cache policy confluence-server || rpm -q confluence-server || confluence-server --version

2. UPGRADE to 8.5.25 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade confluence-server

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade confluence-server

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 8.5.0 (Debian / Ubuntu)

apt-cache madison confluence-server sudo apt install confluence-server=<VERSION_BEFORE_8.5.0> sudo apt-mark hold confluence-server

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

dnf --showduplicates list confluence-server sudo dnf downgrade confluence-server-<VERSION_BEFORE_8.5.0> sudo dnf versionlock add confluence-server

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-2025-22166?

confluence data center: upgrade to 8.5.25, 9.2.7, 10.0.2; confluence server: upgrade to 8.5.25, 9.2.7, 10.0.2. Exact commands for each OS are on this page.

Is CVE-2025-22166 being exploited?

CVE-2025-22166 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-2025-22166 affect?

CVE-2025-22166 affects confluence data center, confluence server. Severity is high (CVSS 7.5). This High severity DoS (Denial of Service) vulnerability was introduced in version 2.0 of Confluence Data Center. This DoS (Denial of Service) vulnerability, with a CVSS Score of 8.3, allows an attacker to cause a resource to be unavaila

How urgent is CVE-2025-22166?

Priority 42/100. High severity; Remotely exploitable, no login, no user action

Software pages

Atlassian Confluence vulnerabilities

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References

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