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VulnerabilityPublished

CVE-2026-13311: ljharb shell-quote · Inefficient Algorithmic Complexity

Affects ljharb shell-quoteSource CVE Database V5

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Not known to be exploited · CVSS 8.7 High · fixed in 1.8.5 : patch ljharb shell-quote soon.

Data as of 6 Nov 2026, 23:24 UTC

CVSS 4.0 base score
8.7High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 29% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 1.8.5
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 25 Jun 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 7 Nov 2026.

What to do

Affected software

ProductAffectedFixed in
ljharbshell-quoteAffected
  • <=1.8.4
Fixed in–
npmshell-quotepkg:npm/shell-quoteOther threatsAffected
  • <=1.8.4
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available in ljharb shell-quote version 1.8.5. Users should upgrade to version 1.8.5 or later to remediate this vulnerability. No other mitigation is indicated.

Description

shell-quote prior to 1.8.5 finalizes parsed tokens in parse() using Array.prototype.concat as a reduce accumulator, which reallocates and copies the entire growing array on every iteration. As a result parse() runs in O(n^2) time relative to the number of input tokens. An attacker who can supply an attacker-controlled string to any code path that calls parse() (no shell metacharacters are required; plain space-separated words suffice) can block the single-threaded Node.js event loop for an extended period with a small input, resulting in a denial of service. There is no code execution or data disclosure; impact is to availability only. Fixed in 1.8.5.

References

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