How severe is CVE-2016-10539?

CVE-2016-10539 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2016-10539 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-10539?

CVE-2016-10539 affects Negotiator Project Negotiator. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2016-10539?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2016-10539 published?

CVE-2016-10539 was published on 2018-05-31 and last updated on 2026-06-17.

CVE-2016-10539

CVE-2016-10539 is a high-severity vulnerability in Negotiator Project Negotiator with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (69th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Negotiator Project Negotiator
Published: 2018-05-31
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2016-10539?: 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.
How severe is CVE-2016-10539?: CVE-2016-10539 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2016-10539 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-10539?: CVE-2016-10539 affects Negotiator Project Negotiator. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2016-10539?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2016-10539 published?: CVE-2016-10539 was published on 2018-05-31 and last updated on 2026-06-17.

References

https://nodesecurity.io/advisories/106

Affected products (1)

cpe:2.3:a:negotiator_project:negotiator:*:*:*:*:*:node.js:*:*

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