CVE-2022-23516Network attack vector

Service interruption via recursive CDATA sanitization

Published Dec 14, 2022 · Updated Nov 3, 2025

Uncontrolled recursion in Loofah 2.2.0 through 2.19.0 allows remote attackers to interrupt service via nested CDATA input. The strip scrubber reparses a CDATA child through Loofah.fragment and scrub!, repeating for nested script elements until Ruby exhausts its call stack and raises SystemStackError. A network-facing application must pass attacker-controlled HTML to an affected Loofah sanitizer; the exception and CPU consumption can interrupt that application.

CVSS severity7.5
High
EPSS probability1.09%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled recursion in Loofah 2.2.0 through 2.19.0 allows remote attackers to interrupt service via nested CDATA input. The strip scrubber reparses a CDATA child through Loofah.fragment and scrub!, repeating for nested script elements until Ruby exhausts its call stack and raises SystemStackError. A network-facing application must pass attacker-controlled HTML to an affected Loofah sanitizer; the exception and CPU consumption can interrupt that application.

The record

CVE
CVE-2022-23516
Published
Dec 14, 2022
Updated
Nov 3, 2025
Vendor
flavorjones
Product
Loofah
Classifications
CWE-674, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 14, 2022CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 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=>= 2.2.0, < 2.19.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

flavorjones · Loofahversion=>= 2.2.0, < 2.19.1

Published CVSS scores

7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5NISTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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-674Uncontrolled Recursion
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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