What is CVE-2026-39878?

CVE-2026-39878 is a critical-severity vulnerability in Chamilo Chamilo-Lms, classified under Cross-site Scripting. CVSS score: 9.3/10. Published 2026-07-20.

How severe is CVE-2026-39878?

Critical severity. CVSS v3 base score is 9.3 out of 10.

XSS in Chamilo Chamilo-Lms

CVE-2026-39878

Chamilo LMS versions 1.11.38 and earlier contain a stored cross-site scripting vulnerability in the user registration form that allows any unauthenticated attacker to execute arbitrary JavaScript in an administrator's browser session, leading to full platform admin account takeover. This has been patched in 1.11.40.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.004 (36.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.3 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N.

Affected products

Chamilo Chamilo-lms — versions <= 1.11.38

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

security-advisories@github.com (x_refsource_CONFIRM)
security-advisories@github.com (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-39878?: CVE-2026-39878 is a critical-severity vulnerability in Chamilo Chamilo-Lms, classified under Cross-site Scripting. CVSS score: 9.3/10. Published 2026-07-20.
How severe is CVE-2026-39878?: Critical severity. CVSS v3 base score is 9.3 out of 10.