Alkacon OpenCms allows remote unauthenticated attackers to obtain sensitive information

published 2026-05-08 6 mo ago modified 2026-10-28 11 d ago also GHSA-rcc6-6q2f-m2cw , EUVD-2023-46797

cvss: 7.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 2.3%; EPSS 2.3% chance of exploitation in 30 days, percentile 83%
public exploits: 0; none known, plus a Nuclei check

Alkacon OpenCms before 10.5.1 allows remote unauthenticated attackers to obtain sensitive information via a cmis-online/query XXE attack on a Chemistry servlet.

Patch / fix

fixed in 1

maven org.opencms:opencms-core 10.5.1

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: partial
Assessed: 6 mo ago (2026-05-08)

Exploit prediction

2.34% chance of exploitation in the next 30 days, higher than 83% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

Nuclei template OpenCMS - XML external entity (XXE) nuclei detection template
github.com https://github.com/projectdiscovery/nuclei-templates/issues/8864 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	7.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
CNA	3.1	7.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
GitHub	3.1	7.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Affected packages

ecosystem	package	affected	fixed in
maven	org.opencms:opencms-core	<10.5.1	10.5.1

Classification

Weakness

CWE-611 Improper Restriction of XML External Entity Reference

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary