CVE-2022-42966Public exploitNetwork attack vector

Application interruption via exponential regex backtracking

Published Nov 9, 2022 · Updated May 1, 2025

Regular expression denial of service in cleo before 2.0.0 allows attackers to interrupt consuming applications via crafted table-cell input. The Table._render_cell path applies a permissive style-tag regular expression with overlapping quantified groups to each Table.set_rows cell, causing exponential backtracking. The caller must pass attacker-controlled cell content; exploitation consumes CPU during rendering and stalls the affected application without reading or changing data.

CVSS severity5.9
Medium
EPSS probability0.95%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Regular expression denial of service in cleo before 2.0.0 allows attackers to interrupt consuming applications via crafted table-cell input. The Table._render_cell path applies a permissive style-tag regular expression with overlapping quantified groups to each Table.set_rows cell, causing exponential backtracking. The caller must pass attacker-controlled cell content; exploitation consumes CPU during rendering and stalls the affected application without reading or changing data.

The record

CVE
CVE-2022-42966
Published
Nov 9, 2022
Updated
May 1, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-1333, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 9, 2022CVE publishedPublication date reported by the CVE source.
  2. May 1, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.9JFrogCVSS:3.1/AV:N/AC:H/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.

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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 exploitPublished

Weakness, pattern, technique

CWE-1333Inefficient Regular Expression Complexity
T1499.004Application or System Exploitation

Public exploit references

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Technologies

Your stack

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Your stack

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