What is CVE-2021-25964?

CVE-2021-25964 is a medium-severity vulnerability in Janeczku Calibre-Web, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2021-10-04.

How severe is CVE-2021-25964?

Medium severity. CVSS v3 base score is 5.4 out of 10.

XSS in Janeczku Calibre-Web

CVE-2021-25964

In “Calibre-web” application, v0.6.0 to v0.6.12, are vulnerable to Stored XSS in “Metadata”. An attacker that has access to edit the metadata information, can inject JavaScript payload in the description field. When a victim tries to open the file, XSS will be triggered.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-10-04 · last modified 2026-06-17.

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: 0.005 (43.7th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 43.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Janeczku Calibre-Web
Ozzieisaacs Calibreweb — versions 0.6.0, unspecified

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25964 (Third Party Advisory)
github.com/janeczku/calibre-web/commit/32e27712f0f71fdec646add20cd78b4ce75acfce (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-25964?: CVE-2021-25964 is a medium-severity vulnerability in Janeczku Calibre-Web, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2021-10-04.
How severe is CVE-2021-25964?: Medium severity. CVSS v3 base score is 5.4 out of 10.