CVE-2026-47733Public exploitNetwork attack vector

Stored XSS via unsanitized markdown image URLs

Published Jun 24, 2026 · Updated Jun 24, 2026

Stored XSS in Rocket.Chat before 8.5.0 allows remote authenticated users to execute JavaScript through crafted markdown images. ImageElement passes the parser-controlled src value directly into anchor href and image src attributes instead of applying the available protocol sanitizer. Exploitation requires a viewer on an older browser to click the rendered image; successful execution can read session data or perform actions as that viewer.

CVSS severity4.4
Medium
EPSS probability0.18%
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 Rocket.Chat before 8.5.0 allows remote authenticated users to execute JavaScript through crafted markdown images. ImageElement passes the parser-controlled src value directly into anchor href and image src attributes instead of applying the available protocol sanitizer. Exploitation requires a viewer on an older browser to click the rendered image; successful execution can read session data or perform actions as that viewer.

The record

CVE
CVE-2026-47733
Published
Jun 24, 2026
Updated
Jun 24, 2026
Vendor
Rocket.Chat Technologies Corp.
Product
Rocket.Chat
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 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=< 8.5.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Rocket.Chat Technologies Corp. · Rocket.Chatversion=< 8.5.0

Published CVSS scores

4.4GitHub, Inc.CVSS:3.1/AV:N/AC:H/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')
T1203Exploitation for Client Execution

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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