CVE-2025-25306: Misskey is an open source, federated social media platform

Q: How do I fix CVE-2025-25306?

misskey: upgrade to 2025.2.1. Exact commands for each OS are on this page.

Q: Is CVE-2025-25306 being exploited?

CVE-2025-25306 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2025-25306 affect?

CVE-2025-25306 affects misskey. Severity is critical (CVSS 9.3). Misskey is an open source, federated social media platform. The patch for CVE-2024-52591 did not sufficiently validate the relation between the `id` and `url` fields of ActivityPub objects. An attacker can forge an object where they claim a

Q: How urgent is CVE-2025-25306?

Priority 39/100. Critical severity; Remotely exploitable, no login, no user action

This month

CRITICAL 9.3REMOTEUPGRADE

CVE-2025-25306 is a critical-severity flaw (CVSS 9.3) affecting misskey. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Misskey is an open source, federated social media platform. The patch for CVE-2024-52591 did not sufficiently validate the relation between the `id` and `url` fields of ActivityPub objects. An attacker can forge an object where they claim authority in the `url` field even if the specific ActivityPub object type require authority in the `id` field. Version 2025.2.1 addresses the issue.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.3 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.2% (top 92%)
CISA exploited list	No
Weakness	CWE-346, CWE-441, CWE-1025
Published	2025-03-10
Last modified	2026-06-17

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

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

Am I affected?

Timeline

2025-03-10 19:15 UTCPublished CVE record published
2026-06-17 09:00 UTCUpdated Record last modified

misskey misskey UPGRADE

Affected: < 2025.2.1

Fixed in: 2025.2.1

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 2025.2.1 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade misskey

Note

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

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-2025-25306?

misskey: upgrade to 2025.2.1. Exact commands for each OS are on this page.

Is CVE-2025-25306 being exploited?

CVE-2025-25306 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-2025-25306 affect?

CVE-2025-25306 affects misskey. Severity is critical (CVSS 9.3). Misskey is an open source, federated social media platform. The patch for CVE-2024-52591 did not sufficiently validate the relation between the `id` and `url` fields of ActivityPub objects. An attacker can forge an object where they claim a

How urgent is CVE-2025-25306?

Priority 39/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2025-66482 MEDIUM 6.5 UPGRADE Misskey is an open source, federated social media platform
CVE-2025-66402 MEDIUM 6.5 UPGRADE Misskey is an open source, federated social media platform
CVE-2026-28433 MEDIUM 4.3 UPGRADE Misskey is an open source, federated social media platform
CVE-2026-28432 HIGH 7.5 UPGRADE Misskey is an open source, federated social media platform
CVE-2026-28431 HIGH 7.5 UPGRADE Misskey is an open source, federated social media platform

References

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