CVE-2026-33737 [Medium] | Security Vulnerability in Chamilo Lms

Chamilo LMS is a learning management system. Prior to 1.11.38 and 2.0.0-RC.3, multiple files use simplexml_load_string() without XXE protection. With LIBXML_NOENT flag, arbitrary server files can be read. This vulnerability is fixed in 1.11.38 and 2.0.0-RC.3.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-04-11	—	0.03%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-04-11

—

0.03%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.3	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:N) Service keeps running; no real outage angle.	1.6	3.6	[email protected]
6.5	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:N) Service keeps running; no real outage angle.	2.8	3.6	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

5.3

3.1

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:N): Service keeps running; no real outage angle.

1.6

3.6

[email protected]

6.5

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:N): Service keeps running; no real outage angle.

2.8

3.6

[email protected]

Affected software / configurations for CVE-2026-33737

Vendor	Product	Version	Raw CPE
chamilo	chamilo_lms	< 1.11.38	cpe:2.3:a:chamilo:chamilo_lms::::::::
chamilo	chamilo_lms	2.0.0	cpe:2.3:a:chamilo:chamilo_lms:2.0.0:alpha1::::::
chamilo	chamilo_lms	2.0.0	cpe:2.3:a:chamilo:chamilo_lms:2.0.0:alpha2::::::
chamilo	chamilo_lms	2.0.0	cpe:2.3:a:chamilo:chamilo_lms:2.0.0:alpha3::::::
chamilo	chamilo_lms	2.0.0	cpe:2.3:a:chamilo:chamilo_lms:2.0.0:alpha4::::::
chamilo	chamilo_lms	2.0.0	cpe:2.3:a:chamilo:chamilo_lms:2.0.0:alpha5::::::
chamilo	chamilo_lms	2.0.0	cpe:2.3:a:chamilo:chamilo_lms:2.0.0:beta1::::::
chamilo	chamilo_lms	2.0.0	cpe:2.3:a:chamilo:chamilo_lms:2.0.0:beta2::::::
chamilo	chamilo_lms	2.0.0	cpe:2.3:a:chamilo:chamilo_lms:2.0.0:beta3::::::
chamilo	chamilo_lms	2.0.0	cpe:2.3:a:chamilo:chamilo_lms:2.0.0:rc1::::::
chamilo	chamilo_lms	2.0.0	cpe:2.3:a:chamilo:chamilo_lms:2.0.0:rc2::::::

References for CVE-2026-33737

URL	Tags
https://github.com/chamilo/chamilo-lms/commit/22b1cb1c609b643765c88654155aba27070c927e	Patch
https://github.com/chamilo/chamilo-lms/commit/af6b7002af7c15825e98fc522e2ead0d00cacaa3	Patch
https://github.com/chamilo/chamilo-lms/security/advisories/GHSA-c4ww-qgf2-v89j	Vendor Advisory

URL

CVE-2026-33737 | Chamilo LMS has an XML External Entity (XXE) Injection

Exploit prediction scoring system (EPSS) score for CVE-2026-33737

Common vulnerability scoring system (CVSS) metrics for CVE-2026-33737

Weakness enumeration for CVE-2026-33737

Affected software / configurations for CVE-2026-33737

References for CVE-2026-33737