XSS in Makeplane Plane

CVE-2025-55203

Plane is open-source project management software. Prior to version 0.28.0, a stored cross-site scripting (XSS) vulnerability exists in the description_html field of Plane. This flaw allows an attacker to inject malicious JavaScript code that is stored and later executed in other users’ browsers. The description_html field is not properly sanitized or escaped. An attacker can submit crafted JavaScript payloads that are saved in the application’s database. When another user views the affected content, the injected code executes in their browser, running in the application’s context and bypassing standard security protections. Successful exploitation can lead to session hijacking, theft of sensitive information, or forced redirection to malicious sites. The vulnerability can also be chained with CSRF attacks to perform unauthorized actions, or leveraged to distribute malware and exploit additional browser vulnerabilities. This issue has been patched in version 0.28.0.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (10.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 10th percentile — 10.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-55203: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-55203?
CVE-2025-55203 is a medium-severity vulnerability in Makeplane Plane, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2025-08-15.
How severe is CVE-2025-55203?
Medium severity. CVSS v3 base score is 5.4 out of 10.
Is CVE-2025-55203 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.