8.7
HIGH CVSS 4.0
CVE-2026-73413
Shescape: Quadratic-time denial of service in flag-protection
Description

Shescape is a simple shell escape library for JavaScript. From 2.1.11 until 2.1.14 and 3.0.1, the flag-protection loop in compose in src/internal/compose.js repeatedly joins and slices flag fragments when flagProtection is enabled, which is the default, making processing quadratic in input size across the escape, escapeAll, quote, and quoteAll APIs. An attacker who can supply a large untrusted input containing many flag fragments can consume CPU and cause denial of service. This issue is fixed in versions 2.1.14 and 3.0.1.

INFO

Published Date :

Aug. 12, 2026, 8:17 p.m.

Last Modified :

Aug. 12, 2026, 8:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-73413 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 HIGH [email protected]
Solution
Update Shescape to a version that addresses quadratic processing performance issues.
  • Update Shescape to version 2.1.14 or later.
  • Update Shescape to version 3.0.1 or later.
  • Disable flagProtection if updating is not possible.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-73413 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-73413 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-73413 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-73413 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Aug. 12, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'ericcornelissen', 'product': 'shescape', 'versions': [{'status': 'affected', 'version': '>= 2.1.11, < 2.1.14'}, {'status': 'affected', 'version': '>= 3.0.0, < 3.0.1'}]}]
    Added Description Shescape is a simple shell escape library for JavaScript. From 2.1.11 until 2.1.14 and 3.0.1, the flag-protection loop in compose in src/internal/compose.js repeatedly joins and slices flag fragments when flagProtection is enabled, which is the default, making processing quadratic in input size across the escape, escapeAll, quote, and quoteAll APIs. An attacker who can supply a large untrusted input containing many flag fragments can consume CPU and cause denial of service. This issue is fixed in versions 2.1.14 and 3.0.1.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-407
    Added CWE CWE-400
    Added Reference https://github.com/ericcornelissen/shescape/commit/43d70b59d09bbe5c3fd02ef08b3a123e977ed9de
    Added Reference https://github.com/ericcornelissen/shescape/commit/b4b34c394e7f9da2775bb75381066b9a228c425f
    Added Reference https://github.com/ericcornelissen/shescape/pull/2649
    Added Reference https://github.com/ericcornelissen/shescape/pull/2651
    Added Reference https://github.com/ericcornelissen/shescape/releases/tag/v2.1.14
    Added Reference https://github.com/ericcornelissen/shescape/releases/tag/v3.0.1
    Added Reference https://github.com/ericcornelissen/shescape/security/advisories/GHSA-gm3r-q2wp-hw87
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.