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CVE-2026-21430: Emlog Cross Site Scripting (CVSS 7)

CVE-2026-21430 is a high severity cross site scripting in Emlog with a CVSS score of 7. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Last updated: Jun 17, 2026

Quick answer

Direct answer

CVE-2026-21430 is a high severity cross site scripting in Emlog with a CVSS score of 7. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Risk scores

CVSS base score
7HIGH
EPSS probability
0.18%
Higher than 7 percent of all CVEs
CISA KEV
Not listed
CVSS metricWhat it means
Attack vector (AV:N)Network: reachable remotely
Attack complexity (AC:L)Low complexity
Attack requirements (AT:N)No attack requirements
Privileges required (PR:N)No privileges required
User interaction (UI:P)Passive user interaction
Confidentiality (VC:N)No confidentiality impact
Integrity (VI:H)High integrity impact
Availability (VA:N)No availability impact

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

About Emlog

CVE-2026-21430 affects Emlog, a product from Emlog. Before acting, confirm where Emlog runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.

What the flaw is

In plain terms: Emlog is an open source website building system. In version 2.5.23, article creation functionality is vulnerable to cross-site request forgery (CSRF). This can lead to a user being forced to post an article with arbitrary, attacker-controlled content. This, when combined with stored cross-site scripting, leads to account takeover. As of time of publication, no known patched versions are available.

The weakness class is Cross Site Scripting. Attacker supplied script runs in another user's browser inside the trusted site.

Based on its CVSS vector, the flaw can be reached over the network, needs no login, and relies on a user taking an action. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Affected versions and timeline

FieldDetail
ProductEmlog
Affected versionsEmlog 2.5.23
PublishedJan 2, 2026
Last modifiedJun 17, 2026
Added to CISA KEVNot listed
Assigning CNAsecurity-advisories@github.com

How to detect it

  • Inventory every instance of Emlog and record the running version against the affected range above.
  • Check external attack surface scans for internet facing instances of the component.
  • Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
  • Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.

How to fix it

  • Apply the fixed version of Emlog named in the vendor advisory.
  • If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
  • Rescan after the change to prove the exposure is gone, then close the ticket.

CTEM action plan

CTEM stageWhat to do for this CVE
ScopeAdd every business service that depends on Emlog to the current CTEM cycle.
DiscoverFind all instances, including shadow and cloud deployments, and record versions and exposure.
PrioritizeRank using EPSS and CVSS together with asset exposure and business impact.
ValidateConfirm the flaw is reachable and exploitable in your environment and that compensating controls work.
MobilizeAssign the fix to the asset owner with a due date matched to the priority, then verify closure.

CWE References

Technical References

Frequently asked questions

CVE-2026-21430 is a high severity cross site scripting in Emlog with a CVSS score of 7. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

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