CVE-2023-2142Public exploitNetwork attack vector

Cross-site scripting via unescaped backslash

Published Nov 26, 2024 · Updated Nov 27, 2024

Cross-site scripting in Mozilla Nunjucks before 3.2.4 allows remote attackers to inject JavaScript through autoescaped template values. The escape routine omitted backslashes from its replacement map and regular expression, allowing one controlled value to escape a quoted JavaScript string before a second value supplied executable code. Exploitation requires two attacker-controlled parameters rendered on the same template line and user interaction with the resulting page, exposing browser-accessible data and actions.

CVSS severity6.1
Medium
EPSS probability0.36%
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 Mozilla Nunjucks before 3.2.4 allows remote attackers to inject JavaScript through autoescaped template values. The escape routine omitted backslashes from its replacement map and regular expression, allowing one controlled value to escape a quoted JavaScript string before a second value supplied executable code. Exploitation requires two attacker-controlled parameters rendered on the same template line and user interaction with the resulting page, exposing browser-accessible data and actions.

The record

CVE
CVE-2023-2142
Published
Nov 26, 2024
Updated
Nov 27, 2024
Vendor
Mozilla
Product
Nunjucks
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 26, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 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 <3.2.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Nunjucksversion=0 <3.2.4

Published CVSS scores

6.1CISA-ADPCVSS: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 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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