CPU exhaustion via unbounded email regex matching
Published Apr 15, 2024 · Updated Feb 13, 2025
Regular expression denial of service in Pydantic 1.x before 1.10.13 and 2.x before 2.4.0 allows remote attackers to exhaust CPU. The validate_email function in pydantic/networks.py applies an unbounded email-pattern match to a less-than sign followed by thousands of spaces, causing excessive backtracking. Exposure requires a consuming application to pass attacker-controlled email text into Pydantic validation; the resulting CPU load can interrupt that application's service.
Summary
What happened
Regular expression denial of service in Pydantic 1.x before 1.10.13 and 2.x before 2.4.0 allows remote attackers to exhaust CPU. The validate_email function in pydantic/networks.py applies an unbounded email-pattern match to a less-than sign followed by thousands of spaces, causing excessive backtracking. Exposure requires a consuming application to pass attacker-controlled email text into Pydantic validation; the resulting CPU load can interrupt that application's service.
The record
- CVE
- CVE-2024-3772
- Published
- Apr 15, 2024
- Updated
- Feb 13, 2025
- Vendor
- Pydantic
- Product
- Pydantic
- Classifications
- CWE-1333, CAPEC-492, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 15, 2024CVE publishedPublication date reported by the CVE source.
- Feb 13, 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=1.0 <1.10.13
- Affected versionversion=2.0
- Affected versionversion=2.0 <2.4.0
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
- Pydantic validate_email ReDoS reproductionproof of concept · demonstrated
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Technologies
Your stack
See the directory against your own environment.
Your stack
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