CVE-2023-3978Network attack vector

Cross-site scripting via unescaped foreign text nodes

Published Aug 2, 2023 · Updated Sep 27, 2024

Cross-site scripting in golang.org/x/net/html before 0.13.0 allows remote attackers to inject script through rendered foreign text nodes. The Render function emits non-HTML-namespace text literally instead of escaping its markup, allowing the serialized output to contain executable HTML. Exploitation requires an application to render attacker-influenced foreign content and a user to load the result, enabling script execution in the user's browser.

CVSS severity6.1
Medium
EPSS probability0.84%
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 golang.org/x/net/html before 0.13.0 allows remote attackers to inject script through rendered foreign text nodes. The Render function emits non-HTML-namespace text literally instead of escaping its markup, allowing the serialized output to contain executable HTML. Exploitation requires an application to render attacker-influenced foreign content and a user to load the result, enabling script execution in the user's browser.

The record

CVE
CVE-2023-3978
Published
Aug 2, 2023
Updated
Sep 27, 2024
Vendor
golang.org/x/net
Product
golang.org/x/net/html
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 2, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 27, 2024Record 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 <0.13.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

golang.org/x/net · golang.org/x/net/htmlversion=0 <0.13.0

Published CVSS scores

6.1NISTCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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

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Your stack

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