CVE-2021-28556Network attack vector

Browser script execution via unsanitized cookie message links

Published Jun 28, 2021 · Updated Sep 17, 2024

DOM-based XSS in Adobe Commerce 2.4.2 and earlier allows remote attackers to execute JavaScript through a crafted mage-messages cookie. The client-side HTML escaper accepts a javascript-scheme href from cookie-derived message markup and inserts it into the storefront DOM. Exploitation requires no credentials but does require a user to interact with the injected link, bounding impact to code execution in that user's browser context.

CVSS severity4.8
Medium
EPSS probability1.40%
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

DOM-based XSS in Adobe Commerce 2.4.2 and earlier allows remote attackers to execute JavaScript through a crafted mage-messages cookie. The client-side HTML escaper accepts a javascript-scheme href from cookie-derived message markup and inserts it into the storefront DOM. Exploitation requires no credentials but does require a user to interact with the injected link, bounding impact to code execution in that user's browser context.

The record

CVE
CVE-2021-28556
Published
Jun 28, 2021
Updated
Sep 17, 2024
Vendor
Adobe
Product
Adobe Commerce
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 28, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record 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=unspecified <=2.3.6-p1
  2. Affected versionversion=unspecified <=2.4.1-p1
  3. Affected versionversion=unspecified <=2.4.2
  4. Affected versionversion=unspecified <=None

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Adobe · Adobe Commerceversion=unspecified <=2.3.6-p1; version=unspecified <=2.4.1-p1; version=unspecified <=2.4.2; version=unspecified <=None

Published CVSS scores

4.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

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