CVE-2022-4876Network attack vector

Cross-site scripting via unvalidated forwarded host

Published Jan 4, 2023 · Updated May 28, 2025

Cross-site scripting in Kaltura mwEmbed 2.96.rc1 and earlier allows remote attackers to execute script via a forwarded host header. DefaultSettings.php copies the first HTTP_X_FORWARDED_HOST value into HTTP_HOST and SERVER_NAME without validating its hostname syntax. The attack requires a user to load the affected response, after which the injected script can read browser-accessible data or modify the page.

CVSS severity6.1
Medium
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Kaltura mwEmbed 2.96.rc1 and earlier allows remote attackers to execute script via a forwarded host header. DefaultSettings.php copies the first HTTP_X_FORWARDED_HOST value into HTTP_HOST and SERVER_NAME without validating its hostname syntax. The attack requires a user to load the affected response, after which the injected script can read browser-accessible data or modify the page.

The record

CVE
CVE-2022-4876
Published
Jan 4, 2023
Updated
May 28, 2025
Vendor
Kaltura
Product
mwEmbed
Classifications
CWE-79
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 4, 2023CVE publishedPublication date reported by the CVE source.
  2. May 28, 2025Record 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=2.96.rc1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Kaltura · mwEmbedversion=2.96.rc1

Published CVSS scores

3.5VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N
6.1NVDCVSS: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.

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')

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

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Your stack

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