CVE-2026-77989Network attack vector

Reflected XSS via unescaped PDF export URL

Published Aug 27, 2026 · Updated Aug 27, 2026

Reflected XSS in JEM - Joomla Event Manager before 5.0.1 allows remote attackers to execute script via a crafted PDF export URL. The buildCurrentPdfLink method copies the current request query string into the PDF button URL, and pdfbutton() emits that value without output encoding. Exploitation requires a victim to open the crafted URL, causing attacker-supplied script to run in the affected site's browser origin.

CVSS severity5.3
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in JEM - Joomla Event Manager before 5.0.1 allows remote attackers to execute script via a crafted PDF export URL. The buildCurrentPdfLink method copies the current request query string into the PDF button URL, and pdfbutton() emits that value without output encoding. Exploitation requires a victim to open the crafted URL, causing attacker-supplied script to run in the affected site's browser origin.

The record

CVE
CVE-2026-77989
Published
Aug 27, 2026
Updated
Aug 27, 2026
Vendor
Joomla Event Manager
Product
JEM - Joomla Event Manager
Classifications
CWE-79
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.0.0-5.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Joomla Event Manager · JEM - Joomla Event Managerversion=1.0.0-5.0.0

Published CVSS scores

5.3Joomla CNACVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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