CVE-2026-77034Network attack vector

Unauthenticated article overwrite via visitor session token

Published Aug 27, 2026 · Updated Aug 27, 2026

Improper access control in JEM 1.0.0 through 5.0.0 allows remote attackers to overwrite and force-publish event-linked articles. The event article update path accepts a visitor's own session token as sufficient authorization to write and publish an article associated with an event. No account or user interaction is required; the consequence is limited to the integrity of event-associated article content.

CVSS severity6.9
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper access control in JEM 1.0.0 through 5.0.0 allows remote attackers to overwrite and force-publish event-linked articles. The event article update path accepts a visitor's own session token as sufficient authorization to write and publish an article associated with an event. No account or user interaction is required; the consequence is limited to the integrity of event-associated article content.

The record

CVE
CVE-2026-77034
Published
Aug 27, 2026
Updated
Aug 27, 2026
Vendor
JEM Team
Product
JEM
Classifications
CWE-284, T1565.001
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

Compare your product and version with the public record. A matching version still requires validation against your environment.

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?

JEM Team · JEMversion=1.0.0-5.0.0

Published CVSS scores

6.9Joomla! ProjectCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/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-284Improper Access Control
T1565.001Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo