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Fencer Vulns
medium 6.1

CVE-2026-47848 json

Reactor Netty WebSocket Client Leaks Credentials On Redirect

published 2026-08-26 2 mo ago modified 2026-09-04 2 mo ago also EUVD-2026-66680

cvss
6.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 17%
public exploits
0
none known

Summary

In specific scenarios involving WebSocket handshake redirects to a different origin, the Reactor Netty WebSocket client may leak credentials. In order for this to happen, the HTTP client must have been explicitly configured to follow redirects. Reactor Netty 1.3.0 - 1.3.6 Reactor Netty 1.1.0 - 1.2.18 Reactor Netty 1.0.52 and earlier

Patch / fix

  • broadcom reactor_netty 1.0.53, 1.2.19, 1.3.6.1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-47848 updated cvss 6.1

io.projectreactor.netty/reactor-netty: Reactor Netty WebSocket client: Information disclosure via credential leak on redirect

  • Red Hat Fuse 7 reactor-netty 0.9.25.RELEASE
    affected: no fix planned “Out of support scope”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected products

  • Spring Reactor Netty

Classification

Weakness
  • CWE-601 URL Redirection to Untrusted Site

References

Sources

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.