CVE-2026-73413Public exploitNetwork attack vector

Denial of service via quadratic flag-fragment processing

Published Aug 12, 2026 · Updated Aug 12, 2026

Algorithmic denial of service in Eric Cornelissen Shescape 2.1.11 through 2.1.13 and 3.0.0 allows attackers to exhaust CPU. The compose function repeatedly joins and slices remaining flag fragments inside its protection loop, making processing quadratic in input length. The default-enabled path is reached through escape, escapeAll, quote, or quoteAll when a consuming application accepts large untrusted inputs containing many flag fragments.

CVSS severity8.7
High
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Algorithmic denial of service in Eric Cornelissen Shescape 2.1.11 through 2.1.13 and 3.0.0 allows attackers to exhaust CPU. The compose function repeatedly joins and slices remaining flag fragments inside its protection loop, making processing quadratic in input length. The default-enabled path is reached through escape, escapeAll, quote, or quoteAll when a consuming application accepts large untrusted inputs containing many flag fragments.

The record

CVE
CVE-2026-73413
Published
Aug 12, 2026
Updated
Aug 12, 2026
Vendor
Eric Cornelissen
Product
Shescape
Classifications
CWE-400, CWE-407, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 12, 2026Record 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=>= 2.1.11, < 2.1.14
  2. Affected versionversion=>= 3.0.0, < 3.0.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Eric Cornelissen · Shescapeversion=>= 2.1.11, < 2.1.14; version=>= 3.0.0, < 3.0.1

Published CVSS scores

8.7GitHub CNACVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-400Uncontrolled Resource Consumption
CWE-407Inefficient Algorithmic Complexity
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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