CVE-2026-4089

CVE-2026-4089 is a medium-severity vulnerability with a CVSS 3.x base score of 6.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Description

The Twittee Text Tweet plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'id' shortcode attribute in all versions up to and including 1.0.8. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes. The ttt_twittee_tweeter() function uses extract() to pull shortcode attributes into local variables and then directly concatenates them into HTML output without any escaping. Specifically, the $id parameter is inserted into an HTML id attribute context without esc_attr(), allowing an attacker to break out of the attribute and inject arbitrary HTML event handlers. Additionally, the $tweet, $content, $balloon, and $theme attributes are similarly injected into inline JavaScript without escaping (lines 87, 93, 101, 117). This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Frequently asked questions

What is CVE-2026-4089?
The Twittee Text Tweet plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'id' shortcode attribute in all versions up to and including 1.0.8. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes. The ttt_twittee_tweeter() function uses extract() to pull shortcode attributes into local variables and then directly concatenates them into HTML output without any escaping. Specifically, the $id parameter is inserted into an HTML id attribute context without esc_attr(), allowing an attacker to break out of the attribute and inject arbitrary HTML event handlers. Additionally, the $tweet, $content, $balloon, and $theme attributes are similarly injected into inline JavaScript without escaping (lines 87, 93, 101, 117). This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
How severe is CVE-2026-4089?
CVE-2026-4089 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-4089 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-4089?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-4089 have an EU (EUVD) identifier?
Yes. CVE-2026-4089 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-24654.
When was CVE-2026-4089 published?
CVE-2026-4089 was published on 2026-04-22 and last updated on 2026-06-17.

References

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