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VulnerabilityPublished Updated

CVE-2026-2736: Alkacon OpenCms · XSS or 'Cross-site Scripting'

Affects Alkacon OpenCmsSource CVE Database V5

0

Not known to be exploited · CVSS 5.1 Medium.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 4.0 base score
5.1Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 19 Feb 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
AlkaconOpenCmsAffected
  • =18.0
Fixed in–

AI-suggested

To mitigate this vulnerability, organizations should immediately review and sanitize all user inputs, especially the 'q' parameter in the /search/index.html endpoint. Implement strict input validation and output encoding to neutralize any embedded scripts before rendering content. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. Use web application firewalls (WAFs) to detect and block malicious payloads targeting this parameter. Monitor web traffic for suspicious requests containing script tags or unusual payloads in the 'q' parameter. If possible, upgrade to a patched version of OpenCms once available. Additionally, educate users about the risks of clicking untrusted links to reduce the likelihood of successful exploitation. Conduct regular security assessments and penetration tests focusing on XSS vulnerabilities in web applications.

Description

Reflected Cross-site Scripting (XSS) in Alkacon's OpenCms v18.0, which allows an attacker to execute JavaScript code in the victim's browser by sending the victim a malicious URL containing the ‘q’ parameter in ‘/search/index.html’. This vulnerability can be exploited to steal sensitive user information such as session cookies, or to perform actions while impersonating the user.

References

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