PatchTheCVECVE-2016-10539: negotiator is an HTTP content negotiator for Node.js and is used by many modules and frameworks including Expr
CVE-2016-10539 is a high-severity flaw (CVSS 7.5) affecting negotiator. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
negotiator is an HTTP content negotiator for Node.js and is used by many modules and frameworks including Express and Koa. The header for "Accept-Language", when parsed by negotiator 0.6.0 and earlier is vulnerable to Regular Expression Denial of Service via a specially crafted string.
Why this priority
- High severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2016-10539?
negotiator: upgrade to newer than 0.6.0. Exact commands for each OS are on this page.
Is CVE-2016-10539 being exploited?
CVE-2016-10539 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2016-10539 affect?
CVE-2016-10539 affects negotiator. Severity is high (CVSS 7.5). negotiator is an HTTP content negotiator for Node.js and is used by many modules and frameworks including Express and Koa. The header for "Accept-Language", when parsed by negotiator 0.6.0 and earlier is vulnerable to Regular Expression Den
How urgent is CVE-2016-10539?
Priority 49/100. High severity; Remotely exploitable, no login, no user action