Security readout for executives and security teams
Plain-English summary
A Node.js dependency called negotiator can be forced to spend excessive CPU parsing a malicious Accept-Language header. Sites using affected versions directly or through frameworks/modules such as Express or Koa may face denial of service risk. The source bundle does not provide CVSS, active exploitation evidence, or a named fixed release.
Executive priority
Prioritize as a routine but time-bound dependency remediation for internet-facing Node.js services. It is not confirmed exploited, but denial of service against common web stacks can still affect availability and customer-facing uptime.
Technical view
CVE-2016-10539 is a Regular Expression Denial of Service issue in negotiator 0.6.0 and earlier when parsing Accept-Language. The weakness maps to CWE-400, uncontrolled resource consumption. Exposure depends on whether an application processes attacker-supplied HTTP Accept-Language headers through this affected module version.
Likely exposure
Most likely exposure is public Node.js web applications or APIs that depend on negotiator <= 0.6.0, directly or transitively through modules and frameworks. The bundle specifically mentions Express and Koa ecosystems, but does not enumerate affected framework versions.
Exploitation context
The bundle describes a specially crafted Accept-Language header causing ReDoS, but provides no KEV listing and no cited evidence of active exploitation. Treat this as remotely triggerable denial-of-service risk where untrusted HTTP headers reach affected parsing code.
Researcher notes
Evidence is limited to the CVE description, affected version statement, CWE, and referenced NodeSecurity advisory URL. No CVSS vector, exploit activity, or explicit fixed release is supplied in the bundle, so remediation should be verified against authoritative package guidance.
Mitigation direction
- Inventory package-lock, npm-shrinkwrap, yarn.lock, or pnpm-lock for negotiator <= 0.6.0.
- Check current maintainer or advisory guidance for the supported fixed version.
- Prioritize remediation for internet-facing Node.js services that parse Accept-Language.
- Apply dependency updates through normal change control and regression testing.
- Consider request filtering or rate limiting if urgent patching is delayed.
Validation and detection
- Confirm whether negotiator is present directly or transitively in production builds.
- Map affected dependency paths to deployed services and public routes.
- Verify runtime applications accept external Accept-Language headers.
- Review dependency advisory output after updating packages.
- Run existing unit and HTTP regression tests after remediation.
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-400: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2016-10539 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
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://nodesecurity.io/advisories/106CVE reference · x_refsource_MISC
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.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.