CVE-2026-5776Public exploitNetwork attack vector

Stored XSS via unescaped email attribute output

Published May 20, 2026 · Updated May 20, 2026

Stored XSS in Online Optimisation Email Encoder before 2.4.7 allows remote attackers to execute scripts via user-supplied email addresses. The plugin writes an attacker-controlled email value into the data-enc-email HTML attribute without attribute escaping, allowing crafted values to inject additional attributes or script-bearing markup. No WordPress account is required, but a visitor must load affected stored content; script execution occurs in that visitor's browser under the site's origin.

CVSS severity6.1
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Online Optimisation Email Encoder before 2.4.7 allows remote attackers to execute scripts via user-supplied email addresses. The plugin writes an attacker-controlled email value into the data-enc-email HTML attribute without attribute escaping, allowing crafted values to inject additional attributes or script-bearing markup. No WordPress account is required, but a visitor must load affected stored content; script execution occurs in that visitor's browser under the site's origin.

The record

CVE
CVE-2026-5776
Published
May 20, 2026
Updated
May 20, 2026
Vendor
Online Optimisation
Product
Email Encoder – Protect Email Addresses and Phone Numbers
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 20, 2026CVE publishedPublication date reported by the CVE source.
  2. May 20, 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=0 <2.4.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Online Optimisation · Email Encoder – Protect Email Addresses and Phone Numbersversion=0 <2.4.7

Published CVSS scores

6.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A: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.

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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 exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

Public exploit references

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

Technologies

Your stack

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Your stack

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