DoS Via Malformed URL with Reactor Netty HTTP Server

published 2020-03-03 6 y ago modified 2026-09-04 2 mo ago also GHSA-hp5x-rqf7-43vf , EUVD-2022-1052

cvss: 6.5; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.2%; EPSS 1.2% chance of exploitation in 30 days, percentile 67%
public exploits: 0; none known

Reactor Netty HttpServer, versions 0.9.3 and 0.9.4, is exposed to a URISyntaxException that causes the connection to be closed prematurely instead of producing a 400 response.

Patch / fix

fixed in 1

maven io.projectreactor.netty:reactor-netty-http 0.9.5

Exploit prediction

1.16% chance of exploitation in the next 30 days, higher than 67% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.0	6.5	CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD	2.0	5.0	AV:N/AC:L/Au:N/C:N/I:N/A:P
GitHub	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem	package	affected	fixed in
maven	io.projectreactor.netty:reactor-netty-http	>=0.9.3, <0.9.5	0.9.5

Affected products

Pivotal Reactor Netty

Classification

Weakness

CWE-20 Improper Input Validation
CWE-755 Improper Handling of Exceptional Conditions

References

pivotal.io /security/cve-2020-5403
web, vendor-advisory
nvd.nist.gov /vuln/detail/CVE-2020-5403
advisory

Sources

CVE List CVE-2020-5403
GitHub Advisory GHSA-hp5x-rqf7-43vf
NVD CVE-2020-5403

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary