CVE-2025-21611: tgstation-server is a production scale tool for BYOND server management

This month

HIGH 8.8UPGRADE

CVE-2025-21611 is a high-severity flaw (CVSS 8.8) affecting tgstation-server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

tgstation-server is a production scale tool for BYOND server management. Prior to 6.12.3, roles used to authorize API methods were incorrectly OR'd instead of AND'ed with the role used to determine if a user was enabled. This allows enabled users access to most, but not all, authorized actions regardless of their permissions. Notably, the WriteUsers right is unaffected so users may not use this bug to permanently elevate their account permissions

Why this priority

High severity

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	0.5% (top 58%)
CISA exploited list	No
Weakness	CWE-285
Published	2025-01-06
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: tgstation13

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-01-06 16:15 UTCPublished CVE record published
2026-06-17 08:43 UTCUpdated Record last modified

tgstation13 tgstation-server UPGRADE

Affected: >= 6.11.0 and < 6.12.3

Fixed in: 6.12.3

Safe to downgrade to: a release before 6.11.0

1. Check installed version

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

2. UPGRADE to 6.12.3 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade tgstation-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 6.11.0 (Debian / Ubuntu)

apt-cache madison tgstation-server sudo apt install tgstation-server=<VERSION_BEFORE_6.11.0> sudo apt-mark hold tgstation-server

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

dnf --showduplicates list tgstation-server sudo dnf downgrade tgstation-server-<VERSION_BEFORE_6.11.0> sudo dnf versionlock add tgstation-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-2025-21611?

tgstation-server: upgrade to 6.12.3. Exact commands for each OS are on this page.

Is CVE-2025-21611 being exploited?

CVE-2025-21611 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-2025-21611 affect?

CVE-2025-21611 affects tgstation-server. Severity is high (CVSS 8.8). tgstation-server is a production scale tool for BYOND server management. Prior to 6.12.3, roles used to authorize API methods were incorrectly OR'd instead of AND'ed with the role used to determine if a user was enabled. This allows enabled

How urgent is CVE-2025-21611?

Priority 41/100. High severity

Related CVEs

CVE-2024-41799 HIGH 8.4 UPGRADE tgstation-server is a production scale tool for BYOND server management

References

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