Security readout for executives and security teams
Plain-English summary
CVE-2021-36716 is a denial-of-service risk in Segment's is-email Node.js package before 1.0.1. If an application passes attacker-controlled text into isEmail(input), specially crafted input can drive excessive CPU use, slowing or interrupting the service.
Executive priority
Treat this as a targeted dependency remediation item, not an emergency from the available evidence. Prioritize exposed customer-facing Node.js services because successful abuse could consume CPU and degrade availability.
Technical view
The issue is a regular expression denial of service flaw in the is-email package. The vulnerable path is applications calling isEmail(input) on untrusted data. The public bundle does not provide CVSS, CWE, exploit details, or affected downstream applications.
Likely exposure
Exposure is most likely in Node.js services, APIs, or forms that depend on Segment is-email before 1.0.1 and validate user-supplied email fields at runtime.
Exploitation context
The source bundle does not show CISA KEV listing or cited active exploitation. Practical risk depends on whether an attacker can repeatedly submit crafted email-like input to a reachable validation path.
Researcher notes
Evidence is narrow but consistent: the flaw affects Segment is-email before 1.0.1 and requires crafted input to isEmail(input). No CVSS, CWE, exploit maturity, or downstream product list is provided in the bundle.
Mitigation direction
- Upgrade Segment is-email to version 1.0.1 or later.
- Check Segment release notes and GitHub releases for vendor guidance.
- Prioritize internet-facing services that validate user-supplied email fields.
- Apply request rate limits around unauthenticated validation endpoints.
Validation and detection
- Inspect package manifests and lockfiles for is-email versions before 1.0.1.
- Trace whether isEmail(input) receives untrusted external input.
- Identify public routes or APIs that perform email validation.
- Confirm dependency updates are deployed in production builds.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CVE-2021-36716 mapping review
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Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/segmentio/is-email/releasesCVE reference · x_refsource_MISC
- https://segment.com/docs/release_notes/2021-07-13-cve-2021-36716/CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.