CVE-2025-4126 | EG-Series <= 2.1.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode

The EG-Series plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's [series] shortcode in all versions up to, and including, 2.1.1 due to insufficient input sanitization and output escaping on user supplied attributes in the shortcode_title function. This makes it possible for authenticated attackers - with contributor-level access and above, on sites with the Classic Editor plugin activated - to inject arbitrary JavaScript code in the titletag attribute that will execute whenever a user access an injected page.

Published: 2025-05-15 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2025-4126 is rated Low Risk (39.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.18%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-4126

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-11 0.05% 0.18% +0.12%
2 2026-02-08 0.03% 0.05% +0.02%
3 2025-11-21 0.03%

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-4126

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
3.1 2.7 [email protected]

Weakness enumeration for CVE-2025-4126

Affected software / configurations for CVE-2025-4126

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-4126

cvelogic Threat Intelligence