What is CVE-2019-13956?

CVE-2019-13956 is a critical-severity vulnerability in Codersclub Discuz\!ml, classified under Code Injection. CVSS score: 9.8/10. Published 2019-07-18.

How severe is CVE-2019-13956?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2019-13956 known to be exploited?

8 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

RCE in Codersclub Discuz\!ml

CVE-2019-13956

Discuz!ML 3.2 through 3.4 allows remote attackers to execute arbitrary PHP code via a modified language cookie, as demonstrated by changing 4gH4_0df5_language=en to 4gH4_0df5_language=en'.phpinfo().'; (if the random prefix 4gH4_0df5_ were used).

Vulnerability class: RCE (Remote Code Execution)

Published 2019-07-18 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.046 (91.4th percentile), scored 2026-10-08.

Low probability of exploitation in the next 30 days, but still tracked. 91st percentile — 91.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.046 · newest: 0.046 · change: 0.000

Affected products

Codersclub Discuz\!ml

Weakness classification (CWE)

CWE-94 — Code Injection

Public proof-of-concept exploits

References

esoln.net/esoln/blog/2019/06/14/discuzml-v-3-x-code-injection-vulnerability/ (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2019-13956?: CVE-2019-13956 is a critical-severity vulnerability in Codersclub Discuz\!ml, classified under Code Injection. CVSS score: 9.8/10. Published 2019-07-18.
How severe is CVE-2019-13956?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2019-13956 known to be exploited?: 8 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.