CVE-2022-25918Public exploitNetwork attack vector

CPU exhaustion via curly-brace regex backtracking

Published Oct 27, 2022 · Updated May 5, 2025

Regular expression denial of service in Eric Cornelissen Shescape 1.5.10 through 1.6.0 allows remote attackers to exhaust CPU via crafted input. The escapeArgBash function applies a complex curly-brace lookahead to untrusted input, causing polynomial backtracking on long opening-brace sequences. Exposure requires escape or escapeAll with interpolation enabled for Bash or an unsupported Unix shell, and payload processing can stall the consuming application.

CVSS severity7.5
High
EPSS probability1.33%
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 Eric Cornelissen Shescape 1.5.10 through 1.6.0 allows remote attackers to exhaust CPU via crafted input. The escapeArgBash function applies a complex curly-brace lookahead to untrusted input, causing polynomial backtracking on long opening-brace sequences. Exposure requires escape or escapeAll with interpolation enabled for Bash or an unsupported Unix shell, and payload processing can stall the consuming application.

The record

CVE
CVE-2022-25918
Published
Oct 27, 2022
Updated
May 5, 2025
Vendor
Eric Cornelissen
Product
Shescape
Classifications
CWE-1333, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 27, 2022CVE publishedPublication date reported by the CVE source.
  2. May 5, 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=1.5.10 <unspecified
  2. Affected versionversion=unspecified <1.6.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Eric Cornelissen · Shescapeversion=1.5.10 <unspecified; version=unspecified <1.6.1

Published CVSS scores

7.5NIST NVDCVSS: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.

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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
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

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Technologies

Your stack

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Your stack

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