HighCVE-2026-67213

nanoid before 5.1.6 Infinite Loop via Zero Size in customAlphabet and customRandom (CVE-2026-67213)

Published 29.07.2026Last modified 23.10.2026Sources: Red Hat, BSI, CVE.org, OSV

What is affected, what to do

Update Nano ID project Nano ID to version 3.3.17, Nano ID project Nano ID to version 5.1.6.

Affected: Nano ID project Nano ID lt 3.0.0..3.3.17
Nano ID project Nano ID lt 5.0.0..5.1.6
Fixed in: Nano ID project Nano ID 3.3.17
Nano ID project Nano ID 5.1.6

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Metrics

8.2

Priority

XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

Source: NVD, CVSS v4

7.5

CVSS v3

Severity High on the scale from 0 to 10.

Source: Red Hat, BSI, CVE.org, OSV

0.3 %

EPSS score

Low — model estimates < 1% exploitation likelihood.

Source: FIRST EPSS, percentile 26.2

Show all metrics

Severity: High
Priority (0–325) The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first? Read in glossary: 68.32 Methodology
Exploit maturity An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack. Read in glossary: no public PoC known
XIEM Effective CVSS XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command. Read in glossary: 8.2 Methodology
CVSS v3 CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions. Read in glossary: 7.5
CVSS v4 CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions. Read in glossary: 8.2
EPSS score The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“. Read in glossary: 0.3 %; Low — model estimates < 1% exploitation likelihood.
EPSS percentile The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking. Read in glossary: 26.2; Elevated — this CVE ranks above at least 10% of all CVEs scored today.
KEV status The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching. Read in glossary: —
Published: 29.07.2026
CISA assessment (SSVC): Exploitation: none known · not automatable · Technical impact: partial; Source: CISA Vulnrichment, as of 29 July 2026
CWE CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect. Read in glossary: CWE-835

Detection rules

No NEOSEC detection rule is available for this vulnerability yet.

Classification under NIS2 and CRA

Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

NIS2 NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management. Read in glossary: High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
CRA The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates. Read in glossary: From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001 ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security. Read in glossary: Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

Description

A flaw was found in nanoid (Nano ID), a small, secure, and URL-friendly unique string ID generator. An attacker could exploit this vulnerability by providing a zero-size input to the customAlphabet or customRandom functions. This would cause an infinite loop, leading to a denial of service (DoS) condition by hanging the application's calling thread.

Source: redhat_csaf, BSI WID Portal, BSI CSAF, NVD (NIST), CVE.org (MITRE), cvelistv5, OSV (Open Source Vulnerabilities)

Affected products

The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

Affected products
		Affected versions	Fixed in
nanoid_project	nanoid	`5.0.0 – < 5.1.6` `3.0.0 – < 3.3.17` `5.0.0 – < 5.1.6` `3.0.0 – < 3.3.17`	`5.1.6` `3.3.17` `5.1.6` `3.3.17`
IBM	App Connect Enterprise	`< 13.0.9.0` `< 12.0.12.30`	`13.0.9.0` `12.0.12.30`

Vendors and products

Weakness classes (CWE)

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
Base
The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.
Entry at MITRE CWE-835

References & sources

github.comnanoid 5.1.6 release notesRelease notes, Product, Release notes
github.comFix commit (reject size of 0)Patch, Patch
vulncheck.comVulnCheck Advisory: nanoid before 5.1.6 Infinite Loop via Zero Size in customAlphabet and customRandomThird-party advisory, Patch, Release notes, Third-party advisory
NVD (NIST)vuln/detail/CVE-2026-67213advisory
github.comai/nanoid/commit/f9d13f150847d117877adee3460a46eceb0cf49bweb
github.comai/nanoidpackage
github.comai/nanoid/releases/tag/3.3.17web
github.comai/nanoid/commit/e10f8d40ce9d1ab47f66d65a16b48086432730d0web
github.comai/nanoid/releases/tag/3.3.18web

Changes to this CVE

Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

08.10.2026Record modifiedVulnCheck

New references:

Show 10 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Affected versions (publisher)	added	—	Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/67xxx/CVE-2026-67213.json">CVE-2026-67213</a>
Reference	added	—	https://github.com/ai/nanoid/commit/cb3626d0f3342fdf179cd425fd9c4fbb92c7d0e7
Reference	added	—	https://github.com/ai/nanoid/releases/tag/5.1.6
Reference	added	—	https://www.vulncheck.com/advisories/nanoid-before-infinite-loop-via-zero-size-in-customalphabet-and-customrandom
Reference	removed	https://github.com/ai/nanoid/commit/cb3626d0f3342fdf179cd425fd9c4fbb92c7d0e7	—
Reference	removed	https://github.com/ai/nanoid/releases/tag/5.1.6	—
Reference	removed	https://www.vulncheck.com/advisories/nanoid-before-infinite-loop-via-zero-size-in-customalphabet-and-customrandom	—
Reference type	removed	https://github.com/ai/nanoid/commit/cb3626d0f3342fdf179cd425fd9c4fbb92c7d0e7 Types: Patch	—
Reference type	removed	https://github.com/ai/nanoid/releases/tag/5.1.6 Types: Product, Release Notes	—
Reference type	removed	https://www.vulncheck.com/advisories/nanoid-before-infinite-loop-via-zero-size-in-customalphabet-and-customrandom Types: Patch, Release Notes, Third Party Advisory	—

Source identifier: disclosure@vulncheck.com

18.08.2026Initial analysis by NVDNVD

Newly listed as affected:

Nanoid Project Nano ID project Nano ID (3.0.0 – before 3.3.17; 5.0.0 – before 5.1.6)

CVSS V3.1: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

New references:

Show 5 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
CVSS	added	—	AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Product configuration	added	—	OR cpe:2.3:a:nanoid_project:nanoid::::::node.js:: versions from (including) 3.0.0 up to (excluding) 3.3.17 cpe:2.3:a:nanoid_project:nanoid::::::node.js:: versions from (including) 5.0.0 up to (excluding) 5.1.6
Reference type	added	—	VulnCheck: https://github.com/ai/nanoid/commit/cb3626d0f3342fdf179cd425fd9c4fbb92c7d0e7 Types: Patch
Reference type	added	—	VulnCheck: https://github.com/ai/nanoid/releases/tag/5.1.6 Types: Product, Release Notes
Reference type	added	—	VulnCheck: https://www.vulncheck.com/advisories/nanoid-before-infinite-loop-via-zero-size-in-customalphabet-and-customrandom Types: Patch, Release Notes, Third Party Advisory

Source identifier: nvd@nist.gov

10.08.2026Record modifiedVulnCheck
1 individual change: Affected versions (publisher)
Show the original change
Individual changes of this event as published by NVD
Type Action Before After
Affected versions (publisher) changed
nanoid
nanoid
Source identifier: disclosure@vulncheck.com

Individual changes of this event as published by NVD
Type	Action	Before	After
Affected versions (publisher)	changed	nanoid	nanoid

29.07.2026Record modifiedCISA ADP

CISA assessment (SSVC): exploitation: none known, automatable: no

Show the original change

Individual changes of this event as published by NVD
Type	Action	Before	After
SSVC assessment	added	—	{"id":"CVE-2026-67213","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-07-29T14:41:51.480372Z"}

Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

29.07.2026ReceivedVulnCheck

CVSS V4.0: AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS V3.1: AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness type: CWE-835

Description added or changed

New references:

Show 8 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Affected versions (publisher)	added	—	nanoid
Description	added	—	nanoid (Nano ID) before 5.1.6 contains an infinite loop in the customAlphabet and customRandom functions. When these functions are configured with a size of 0, the internal generation loop never satisfies its exit condition and spins indefinitely, hanging the calling thread. An application that passes an unvalidated, attacker-controlled size of 0 to these functions is exposed to a denial-of-service condition.
CVSS	added	—	AV:N/AC:L/AT:P/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
CVSS	added	—	AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness type (CWE)	added	—	CWE-835
Reference	added	—	https://github.com/ai/nanoid/commit/cb3626d0f3342fdf179cd425fd9c4fbb92c7d0e7
Reference	added	—	https://github.com/ai/nanoid/releases/tag/5.1.6
Reference	added	—	https://www.vulncheck.com/advisories/nanoid-before-infinite-loop-via-zero-size-in-customalphabet-and-customrandom

Source identifier: disclosure@vulncheck.com

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<a href="https://intel.neosec.eu/en/cve/CVE-2026-67213"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-67213.svg?lang=en" alt="CVE-2026-67213 – NEOSEC Intel" height="20"></a>