CVE-2022-21648Network attack vector

Cross-site scripting via complex string expressions

Published Jan 4, 2022 · Updated Apr 23, 2025

Sandbox escape in affected Nette Foundation Latte 2.8, 2.9, and 2.10 releases allows remote attackers to inject script into generated pages. PhpWriter validateTokens accepts complex variable interpolation in double-quoted strings while a sandbox policy is active, so crafted template expressions pass compilation and reach generated output. Exploitation requires an application to enable the sandbox, accept an untrusted template, and serve its rendered page to a victim; the resulting script executes in that victim’s browser context.

CVSS severity8.2
High
EPSS probability0.82%
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

Sandbox escape in affected Nette Foundation Latte 2.8, 2.9, and 2.10 releases allows remote attackers to inject script into generated pages. PhpWriter validateTokens accepts complex variable interpolation in double-quoted strings while a sandbox policy is active, so crafted template expressions pass compilation and reach generated output. Exploitation requires an application to enable the sandbox, accept an untrusted template, and serve its rendered page to a victim; the resulting script executes in that victim’s browser context.

The record

CVE
CVE-2022-21648
Published
Jan 4, 2022
Updated
Apr 23, 2025
Vendor
Nette Foundation
Product
Latte
Classifications
CWE-790, CWE-79, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 4, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 2025Record 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=>= 2.10.0, < 2.10.8
  2. Affected versionversion=>= 2.8.0, < 2.8.8
  3. Affected versionversion=>= 2.9.0, < 2.9.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Nette Foundation · Latteversion=>= 2.10.0, < 2.10.8; version=>= 2.8.0, < 2.8.8; version=>= 2.9.0, < 2.9.6

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
8.2GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/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-790Improper Filtering of Special Elements
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript/JScript

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