CVE-2023-36053Network attack vector

Service interruption via unbounded domain-label validation

Published Jul 3, 2023 · Updated Nov 4, 2025

ReDoS in Django 3.2 before 3.2.20, 4.1 before 4.1.10, and 4.2 before 4.2.3 allows remote attackers to interrupt services. EmailValidator and URLValidator apply regular expressions to unbounded values containing very large numbers of domain labels, causing excessive CPU-consuming match work. Exploitation requires an application to pass attacker-controlled email or URL data to either validator; the impact is request delay or service interruption, not data disclosure or modification.

CVSS severity8.7
High
EPSS probability2.98%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

ReDoS in Django 3.2 before 3.2.20, 4.1 before 4.1.10, and 4.2 before 4.2.3 allows remote attackers to interrupt services. EmailValidator and URLValidator apply regular expressions to unbounded values containing very large numbers of domain labels, causing excessive CPU-consuming match work. Exploitation requires an application to pass attacker-controlled email or URL data to either validator; the impact is request delay or service interruption, not data disclosure or modification.

The record

CVE
CVE-2023-36053
Published
Jul 3, 2023
Updated
Nov 4, 2025
Vendor
Debian
Product
Debian GNU/Linux
Classifications
CWE-1333, T1499.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 3, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 4, 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=10.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Debian · Debian GNU/Linuxversion=10.0
Fedora Project · Fedora Linuxversion=37
Django Software Foundation · Djangoversion=*

Published CVSS scores

8.7GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA: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.

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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-1333Inefficient Regular Expression Complexity
T1499.002Endpoint Denial of Service: Service Exhaustion Flood

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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