CVE-2011-4586

CRLF injection vulnerability in calendar/set.php in the Calendar subsystem in Moodle 1.9.x before...

5.0 Medium

CRLF injection vulnerability in calendar/set.php in the Calendar subsystem in Moodle 1.9.x before 1.9.15, 2.0.x before 2.0.6, and 2.1.x before 2.1.3 allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via unspecified vectors.

Exploit likelihood

2.10%Up 0.9 points since Feb 4, 2022

What each source reports

NVD Score used5.0

Record: CVE-2011-4586
CVSS 2.0: 5.0 MediumAV:N/AC:L/Au:N/C:N/I:P/A:N
Updated: 2026-11-02

CVE ListNo score

Record: CVE-2011-4586
Updated: 2026-11-02

EUVDEUVD-2011-4511No score

Record: EUVD-2011-4511
Updated: 2026-11-03

GitHub AdvisoriesGHSA-5hc2-8542-698wNo score

CRLF injection vulnerability in calendar/set.php in the Calendar subsystem in Moodle 1.9.x before...

Record: GHSA-5hc2-8542-698w
Updated: 2026-11-02

Affected products

moodle

Affected packages

Affected packages
Package	Affected	Fixed
`moodle` Debian:6.0 From an advisory covering 11 CVEs	before 1.9.9.dfsg2-2.1+squeeze3, plus listed versions 1.9.9.dfsg2-2.11.9.9.dfsg2-2.1+squeeze11.9.9.dfsg2-2.1+squeeze2	1.9.9.dfsg2-2.1+squeeze3

History

History
Recorded	Changed	Sources
Nov 6, 2026	affected, facts
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2011-4586 is a medium vulnerability (CVSS 5.0) in Moodle, published February 29, 2012. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.10%, the 81st percentile. No source names a fixed version.