CVE-2025-66020
This High severity DoS (Denial of Service) vulnerability was introduced in versions 9.1.1, 9.2.0, 9.3.1, 9.4.0, 9.5.1, 10.1.2, and 10.2.0 of Confluence Data Center. This DoS (Denial of Service) vulnerability, with a CVSS Score of 7.5 and a CVSS Vector of CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H allows an unauthenticated 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 which has no impact to confidentiality, no impact to integrity, high impact to availability, and requires no user interaction. Atlassian recommends that Confluence Data Center customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions: * Confluence Data Center 9.2: Upgrade to a release greater than or equal to 9.2.19 * Confluence Data Center 10.2: Upgrade to a release greater than or equal to 10.2.10 See the release notes (https://confluence.atlassian.com/doc/confluence-release-notes-327.html). You can download the latest version of Confluence Data Center from the download center (https://www.atlassian.com/software/confluence/download-archives). The National Vulnerability Database provides the following description for this vulnerability: Valibot helps validate data using a schema. In versions from 0.31.0 to 1.1.0, the EMOJI_REGEX used in the emoji action is vulnerable to a Regular Expression Denial of Service (ReDoS) attack. A short, maliciously crafted string (e.g., <100 characters) can cause the regex engine to consume excessive CPU time (minutes), leading to a Denial of Service (DoS) for the application. This issue has been patched in version 1.2.0.
EPSS 0.11% · 28.7th percentile
Risk Scores
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Atlassian | Confluence Data Center |
Exploit Intelligence
- CIRCL seen: CVE-2025-66020 (circl-sighting)
- https://github.com/open-circle/valibot/security/advisories/GHSA-vqpr-j7v3-hqw9 (circl)
- https://github.com/open-circle/valibot/commit/cfb799db301a953a0950d5c05a34a3ab121262dc (circl)
- 2.yaml (github-poc)
- 2.yaml (github-poc)
- 2.yaml (github-poc)
- 2.yaml (github-poc)
- 2.yaml (github-poc)
- 2.yaml (github-poc)
- 2.yaml (github-poc)
…and 1 more exploits
Timeline
- Nov 26, 2025 CVE Published
- Nov 26, 2025 EPSS Score
- Nov 26, 2025 PoC Published
- Dec 1, 2025 EPSS Score
- Dec 5, 2025 EPSS Score
- Dec 10, 2025 EPSS Score
- Dec 15, 2025 EPSS Score
- Dec 19, 2025 EPSS Score
- Dec 24, 2025 EPSS Score
- Dec 29, 2025 EPSS Score
- Jan 2, 2026 EPSS Score
- Jan 7, 2026 EPSS Score