CPU exhaustion via backtracking SVG attribute regex
Published Dec 14, 2022 · Updated Nov 3, 2025
Regular expression DoS in flavorjones Loofah before 2.19.1 allows remote attackers to exhaust CPU during SVG sanitization. The HTML5 attribute scrubber applies a backtracking regular expression to URL values in SVG attributes instead of parsing their component values. Exploitation requires an application to pass attacker-controlled SVG attribute content to the affected sanitizer, and successful abuse hangs the processing worker through sustained CPU consumption.
Summary
What happened
Regular expression DoS in flavorjones Loofah before 2.19.1 allows remote attackers to exhaust CPU during SVG sanitization. The HTML5 attribute scrubber applies a backtracking regular expression to URL values in SVG attributes instead of parsing their component values. Exploitation requires an application to pass attacker-controlled SVG attribute content to the affected sanitizer, and successful abuse hangs the processing worker through sustained CPU consumption.
The record
- CVE
- CVE-2022-23514
- Published
- Dec 14, 2022
- Updated
- Nov 3, 2025
- Vendor
- flavorjones
- Product
- Loofah
- Classifications
- CWE-1333, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 14, 2022CVE publishedPublication date reported by the CVE source.
- 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.
- Affected versionversion=< 2.19.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- Loofah slow-regex regression payloadproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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