CVE-2026-64628Public exploitNetwork attack vector

Stored XSS via unencoded shortcode handler attributes

Published Jul 21, 2026 · Updated Jul 21, 2026

Stored XSS in Grav Shortcode Core 6.2.1 and earlier allows remote authenticated users to execute JavaScript in page viewers' browsers. Security::detectXss accepts shortcode input without a literal less-than sign, while ColorShortcode.php and related handlers place parameters into HTML attributes without encoding. The attack requires admin.pages permission; a quote closes the attribute, and the stored handler runs for visitors or administrators with access to session actions.

CVSS severity5.1
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

Stored XSS in Grav Shortcode Core 6.2.1 and earlier allows remote authenticated users to execute JavaScript in page viewers' browsers. Security::detectXss accepts shortcode input without a literal less-than sign, while ColorShortcode.php and related handlers place parameters into HTML attributes without encoding. The attack requires admin.pages permission; a quote closes the attribute, and the stored handler runs for visitors or administrators with access to session actions.

The record

CVE
CVE-2026-64628
Published
Jul 21, 2026
Updated
Jul 21, 2026
Vendor
Grav
Product
Grav
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 21, 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 <=6.2.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Grav · Gravversion=0 <=6.2.1

Published CVSS scores

5.1VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
5.4VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/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.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript

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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